diff --git a/.github/workflows/codeql.yml b/.github/workflows/codeql.yml
new file mode 100644
index 000000000..286f9d079
--- /dev/null
+++ b/.github/workflows/codeql.yml
@@ -0,0 +1,73 @@
+name: CodeQL
+
+# Static analysis for the TypeScript tree. This is GitHub's default setup
+# expressed as a workflow file rather than enabled from the repository
+# settings, so the query suite, the excluded paths and the schedule are
+# reviewable in the diff like everything else here.
+#
+# Deliberately NOT on `push: main`. The weekly run already analyses the
+# default branch, which is what keeps the Security tab current, and every
+# change reaches `main` through a pull request that is analysed on the way
+# in. Adding a push trigger would analyse the same tree a second time
+# minutes later for no additional signal.
+on:
+  pull_request:
+    branches: [main]
+  schedule:
+    # Mondays, 04:27 UTC. Off the hour so the run does not queue behind
+    # everyone else's midnight cron.
+    - cron: "27 4 * * 1"
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: codeql-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  analyze:
+    name: Analyse javascript-typescript
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+    permissions:
+      contents: read
+      # Required to write the results into the repository's code-scanning
+      # alerts. Free for public repositories.
+      security-events: write
+      # Required by the CodeQL action to read workflow run metadata.
+      actions: read
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+
+      # `build-mode: none` is the correct mode for JavaScript/TypeScript —
+      # CodeQL extracts from source and needs neither a compile step nor
+      # installed dependencies.
+      #
+      # The excluded paths are all generated or vendored output. Chief
+      # among them is `src/generated`, the ~9 MB Prisma client with a
+      # 224 KB inline schema literal in it: extracting that costs real
+      # minutes and can produce nothing actionable, because nobody edits
+      # it and the fix for anything found there is `pnpm prisma generate`.
+      - name: Initialise CodeQL
+        uses: github/codeql-action/init@5595ccaf912efad79be6eef63a5619ff05969be3 # v4.37.6
+        with:
+          languages: javascript-typescript
+          build-mode: none
+          config: |
+            paths-ignore:
+              - src/generated
+              - .next
+              - dist
+              - coverage
+              - playwright-report
+              - test-results
+              - public
+
+      - name: Analyse
+        uses: github/codeql-action/analyze@5595ccaf912efad79be6eef63a5619ff05969be3 # v4.37.6
+        with:
+          category: "/language:javascript-typescript"
diff --git a/.github/workflows/integration.yml b/.github/workflows/integration.yml
index ceb9557f5..a4add73d3 100644
--- a/.github/workflows/integration.yml
+++ b/.github/workflows/integration.yml
@@ -10,21 +10,21 @@ permissions:
   contents: read
 
 jobs:
-  # The suite outgrew a single runner: 128 files took ~13 minutes when the
-  # 25-minute guard was written, and the v1.37 sharing work took it to 173
-  # files and past 25 minutes of wall clock, so every run died at the timeout
-  # with every test to that point green. The guard's own rule applies — split,
-  # don't raise — so the files run as two vitest shards. Each shard boots its
-  # own Postgres testcontainer; the timeout stays a hang detector, sized so a
-  # healthy half-suite clears it on a slow runner.
+  # The suite outgrew a single runner, and then a half-suite outgrew a slow
+  # one: two shards cleared in ~14 minutes on a quiet day, but with six pull
+  # requests running side by side the larger shard hit the same 25-minute
+  # guard the split was meant to escape. Three shards keep the biggest slice
+  # around 60 files, which clears the guard with real headroom even on the
+  # slowest runner observed. Each shard boots its own Postgres testcontainer;
+  # the timeout stays a hang detector, not a performance budget.
   shard:
     runs-on: ubuntu-latest
     timeout-minutes: 25
     strategy:
       fail-fast: false
       matrix:
-        shard: [1, 2]
-    name: integration shard ${{ matrix.shard }}/2
+        shard: [1, 2, 3]
+    name: integration shard ${{ matrix.shard }}/3
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
 
@@ -44,7 +44,7 @@ jobs:
       # vitest a stray positional argument and the shard flag never applies —
       # both "shards" then run the full suite. Proven by a paired local run
       # before this workflow shipped.
-      - run: pnpm exec vitest run --config vitest.integration.config.mts --shard=${{ matrix.shard }}/2
+      - run: pnpm exec vitest run --config vitest.integration.config.mts --shard=${{ matrix.shard }}/3
         env:
           # The integration suite boots a Postgres testcontainer and points
           # Prisma at it via DATABASE_URL set inside `tests/integration/setup.ts`.
diff --git a/.github/workflows/scorecard.yml b/.github/workflows/scorecard.yml
new file mode 100644
index 000000000..0fb4bcd82
--- /dev/null
+++ b/.github/workflows/scorecard.yml
@@ -0,0 +1,60 @@
+name: OpenSSF Scorecard
+
+# Automated checks against the OpenSSF's supply-chain criteria: are Actions
+# pinned by SHA, is there a security policy, are dependencies updated
+# automatically, is the release pipeline signed, is there a fuzzing or a
+# static-analysis story. Most of what it looks for this repository already
+# does; the value is that it keeps looking after the person who set it up
+# has moved on to something else.
+#
+# `publish_results: true` sends the result to the OpenSSF's public API,
+# which is what makes the score citable by anyone evaluating the project
+# without asking for CI access. Nothing about the code or its contents
+# leaves; the checks read repository metadata and the workflow files.
+on:
+  # Re-score when a branch-protection rule changes, since several checks
+  # read exactly that.
+  branch_protection_rule:
+  schedule:
+    # Tuesdays, 07:20 UTC.
+    - cron: "20 7 * * 2"
+  workflow_dispatch:
+
+permissions: read-all
+
+jobs:
+  analysis:
+    name: Score supply-chain practices
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    permissions:
+      # Write the findings into the repository's code-scanning alerts.
+      security-events: write
+      # Publish the result to the public API. This is an OIDC token
+      # exchange, the same mechanism the release workflow uses for keyless
+      # image signing; no long-lived credential is involved.
+      id-token: write
+      contents: read
+      actions: read
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          # Scorecard reads the repository through the API, not through the
+          # checkout, and leaving the token in `.git/config` would hand it
+          # to anything else running in the job.
+          persist-credentials: false
+
+      - name: Run analysis
+        uses: ossf/scorecard-action@2d1146689b8cda280b9bc96326124645441f03bc # v2.4.4
+        with:
+          results_file: scorecard-results.sarif
+          results_format: sarif
+          publish_results: true
+
+      - name: Upload results
+        uses: github/codeql-action/upload-sarif@5595ccaf912efad79be6eef63a5619ff05969be3 # v4.37.6
+        with:
+          sarif_file: scorecard-results.sarif
+          category: scorecard
diff --git a/.github/workflows/trivy.yml b/.github/workflows/trivy.yml
new file mode 100644
index 000000000..235c8ea63
--- /dev/null
+++ b/.github/workflows/trivy.yml
@@ -0,0 +1,164 @@
+name: Trivy Scheduled Scan
+
+# Two scans that the per-change gates cannot do, on a daily cadence.
+#
+# What already exists and is NOT repeated here:
+#   - `security.yml` → `dependency-audit` runs `pnpm audit --prod` on every
+#     push and pull request, blocking on HIGH/CRITICAL.
+#   - `security.yml` → `docker-security` builds the image on a push to `main`
+#     and runs `trivy image` against it, blocking on HIGH/CRITICAL.
+#
+# Both are change-triggered, and both answer "is this change safe". Neither
+# answers "is what we shipped last week still safe", because an advisory
+# published today lands against an image nobody is about to rebuild. That is
+# what the schedule is for. There is deliberately no push or pull_request
+# trigger: adding one would run the same scan the `docker-security` job
+# already ran, minutes later, on the same tree.
+on:
+  schedule:
+    # Daily, 05:17 UTC.
+    - cron: "17 5 * * *"
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: trivy-scheduled
+  cancel-in-progress: true
+
+jobs:
+  filesystem:
+    name: Lockfile (including dev dependencies)
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    permissions:
+      contents: read
+      security-events: write
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+
+      # `pnpm audit --prod` is the blocking gate and it is scoped to
+      # production dependencies on purpose: a dev-only advisory should not
+      # stop a release. The gap that scoping leaves is that "dev dependency"
+      # and "not in the image" are not the same statement.
+      #
+      # `pdfjs-dist` is the worked example. It sits in `devDependencies`,
+      # and `src/lib/documents/rasterize-pdf.ts` imports it at runtime, so
+      # Next's standalone output tracing copies it into the production
+      # image. `pnpm audit --prod` cannot see it. This scan can: without
+      # the flag Trivy reads 627 packages out of `pnpm-lock.yaml`, with it
+      # 1455, and `pdfjs-dist` is only in the second set.
+      #
+      # Trivy's own `--help` lists the flag as supported for npm, yarn and
+      # gradle. It works on `pnpm-lock.yaml` too; the help text is behind
+      # the parser. Verified against this repository before this workflow
+      # was written, and worth re-checking if the package count ever
+      # collapses back to the production figure.
+      #
+      # Report-only, and that is a deliberate choice rather than a soft
+      # one. The findings this widening surfaces are overwhelmingly
+      # transitive dev-tool advisories with fixes available upstream;
+      # failing the run on them from day one produces a red badge that gets
+      # muted within a week, and a muted signal is worse than none. The
+      # SARIF upload puts every finding in the repository's code-scanning
+      # alerts, which persist, notify, and can be triaged one at a time.
+      # The blocking answer to "does this ship" stays where it is, in
+      # `security.yml`.
+      - name: Trivy filesystem scan
+        uses: aquasecurity/trivy-action@ed142fd0673e97e23eac54620cfb913e5ce36c25 # v0.36.0
+        env:
+          # No action input maps to `--include-dev-deps`; Trivy reads every
+          # flag from a `TRIVY_`-prefixed environment variable, so this is
+          # the documented way to reach it through the action.
+          TRIVY_INCLUDE_DEV_DEPS: "true"
+        with:
+          scan-type: fs
+          scan-ref: .
+          scanners: vuln
+          format: sarif
+          output: trivy-filesystem.sarif
+          severity: "CRITICAL,HIGH,MEDIUM"
+          limit-severities-for-sarif: true
+          exit-code: "0"
+          # Generated Prisma client. Nobody edits it, the fix for anything
+          # found in it is `pnpm prisma generate`, and it is ~9 MB.
+          skip-dirs: src/generated
+
+      - name: Upload results
+        uses: github/codeql-action/upload-sarif@5595ccaf912efad79be6eef63a5619ff05969be3 # v4.37.6
+        with:
+          sarif_file: trivy-filesystem.sarif
+          category: trivy-filesystem
+
+  published-image:
+    name: Published image
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    permissions:
+      contents: read
+      packages: read
+      security-events: write
+
+    steps:
+      # The `docker-security` job scans an image it just built from the
+      # current `main`. This one scans the image operators actually pull,
+      # which is the one built from the last release tag and unchanged
+      # since. The two answer different questions and the gap between them
+      # widens every day a release stays out.
+      #
+      # Trivy resolves the multi-arch manifest to the runner's platform, so
+      # this covers `linux/amd64`. The arm64 manifest shares every
+      # application layer and differs only in native binaries.
+      - name: Log in to GitHub Container Registry
+        uses: docker/login-action@dbcb813823bdd20940b903addbd779551569679f # v4.6.0
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      # `.trivyignore` lives at the repository root and Trivy reads it
+      # automatically, so the suppressions the blocking gate already
+      # carries apply here too and the two scans cannot disagree about
+      # what is accepted.
+      - name: Checkout for .trivyignore
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+
+      # Fails on CRITICAL only. A critical advisory against the image
+      # self-hosters are running right now is worth a red badge and a
+      # notification; HIGH goes to code scanning with everything else,
+      # because the release pipeline already refuses to publish an image
+      # carrying one and anything that appears here appeared after the
+      # fact.
+      - name: Trivy published-image scan
+        uses: aquasecurity/trivy-action@ed142fd0673e97e23eac54620cfb913e5ce36c25 # v0.36.0
+        with:
+          scan-type: image
+          image-ref: ghcr.io/mbombeck/healthlog:latest
+          scanners: vuln
+          format: sarif
+          output: trivy-published-image.sarif
+          severity: "CRITICAL,HIGH,MEDIUM"
+          limit-severities-for-sarif: true
+          exit-code: "0"
+
+      - name: Upload results
+        uses: github/codeql-action/upload-sarif@5595ccaf912efad79be6eef63a5619ff05969be3 # v4.37.6
+        with:
+          sarif_file: trivy-published-image.sarif
+          category: trivy-published-image
+
+      # Separate table pass so the SARIF upload above always runs, even
+      # when this one fails the job. A scan whose failure suppresses its
+      # own report is a scan you have to re-run by hand to read.
+      - name: Fail on a critical finding in the published image
+        uses: aquasecurity/trivy-action@ed142fd0673e97e23eac54620cfb913e5ce36c25 # v0.36.0
+        with:
+          scan-type: image
+          image-ref: ghcr.io/mbombeck/healthlog:latest
+          scanners: vuln
+          format: table
+          severity: "CRITICAL"
+          exit-code: "1"
diff --git a/docs/api/openapi.yaml b/docs/api/openapi.yaml
index 92583d744..357b9cfae 100644
--- a/docs/api/openapi.yaml
+++ b/docs/api/openapi.yaml
@@ -9147,6 +9147,16 @@ paths:
                   type: number
                 referenceHigh:
                   type: number
+                sourceReferenceLow:
+                  type: number
+                sourceReferenceHigh:
+                  type: number
+                sourceReferenceText:
+                  anyOf:
+                    - type: string
+                      maxLength: 120
+                    - type: string
+                      const: ""
                 takenAt:
                   type: string
                   format: date-time
@@ -9254,6 +9264,22 @@ paths:
                   anyOf:
                     - type: number
                     - type: "null"
+                sourceReferenceLow:
+                  anyOf:
+                    - type: number
+                    - type: "null"
+                sourceReferenceHigh:
+                  anyOf:
+                    - type: number
+                    - type: "null"
+                sourceReferenceText:
+                  anyOf:
+                    - anyOf:
+                        - type: string
+                          maxLength: 120
+                        - type: string
+                          const: ""
+                    - type: "null"
                 takenAt:
                   type: string
                   format: date-time
@@ -9430,6 +9456,12 @@ paths:
                         type: number
                       referenceHigh:
                         type: number
+                      referenceText:
+                        anyOf:
+                          - type: string
+                            maxLength: 120
+                          - type: string
+                            const: ""
                       takenAt:
                         type: string
                         format: date-time
@@ -11616,6 +11648,11 @@ paths:
                       anyOf:
                         - type: number
                         - type: "null"
+                    referenceText:
+                      anyOf:
+                        - type: string
+                          maxLength: 120
+                        - type: "null"
                     effectiveDate:
                       anyOf:
                         - type: string
@@ -32974,6 +33011,30 @@ components:
           anyOf:
             - type: number
             - type: "null"
+        catalogReferenceLow:
+          anyOf:
+            - type: number
+            - type: "null"
+        catalogReferenceHigh:
+          anyOf:
+            - type: number
+            - type: "null"
+        sourceReferenceLow:
+          anyOf:
+            - type: number
+            - type: "null"
+        sourceReferenceHigh:
+          anyOf:
+            - type: number
+            - type: "null"
+        sourceReferenceText:
+          anyOf:
+            - type: string
+            - type: "null"
+        referenceOrigin:
+          $ref: "#/components/schemas/LabReferenceRangeOrigin"
+        referenceDivergesFromCatalog:
+          type: boolean
         takenAt:
           type: string
         source:
@@ -32996,6 +33057,13 @@ components:
         - unit
         - referenceLow
         - referenceHigh
+        - catalogReferenceLow
+        - catalogReferenceHigh
+        - sourceReferenceLow
+        - sourceReferenceHigh
+        - sourceReferenceText
+        - referenceOrigin
+        - referenceDivergesFromCatalog
         - takenAt
         - source
         - hasNote
@@ -33003,12 +33071,31 @@ components:
         - createdAt
         - updatedAt
       additionalProperties: false
-      description: A stored lab result. Exactly one of `value` (numeric) or `valueText` (qualitative, e.g. "negativ") is
-        non-null; `rangeStatus` is always `unknown` for a qualitative row (no number to classify). `biomarkerId` links
-        the user-scoped catalog marker (null for legacy free-text rows); when linked, `analyte` / `unit` /
-        `referenceLow` / `referenceHigh` are RESOLVED server-side from the Biomarker — the client renders them and never
-        recomputes the range. The encrypted note is never echoed in list rows; `hasNote` flags its presence and the
-        single-resource GET returns the decrypted `note`.
+      description: >-
+        A stored lab result. Exactly one of `value` (numeric) or `valueText` (qualitative, e.g. "negativ") is non-null;
+        `rangeStatus` is always `unknown` for a qualitative row (no number to classify). `biomarkerId` links the
+        user-scoped catalog marker (null for legacy free-text rows); when linked, `analyte` / `unit` are RESOLVED
+        server-side from the Biomarker.
+
+
+        Three reference windows ride on the row and the server says which one applies. `referenceLow` / `referenceHigh`
+        are the window IN FORCE and the one `rangeStatus` was computed from — read these to render the range and you are
+        correct without doing any resolution of your own. `sourceReferenceLow` / `sourceReferenceHigh` /
+        `sourceReferenceText` are the range this reading's own report printed (the text verbatim, kept even when no
+        numbers could be read out of it). `catalogReferenceLow` / `catalogReferenceHigh` are the Biomarker band.
+        `referenceOrigin` names the winner and `referenceDivergesFromCatalog` is true when the report's window and the
+        catalog band state different limits — a surface showing only one of the two is showing a partial answer. The
+        client renders these values and never recomputes the range. The encrypted note is never echoed in list rows;
+        `hasNote` flags its presence and the single-resource GET returns the decrypted `note`.
+    LabReferenceRangeOrigin:
+      type: string
+      enum:
+        - source
+        - catalog
+        - none
+      description: Which window `referenceLow` / `referenceHigh` came from. `source` = the range printed on this reading's own
+        report, which wins for that reading because it is the window the physician evaluated the value against.
+        `catalog` = the user's Biomarker band, the net for readings with no printed range. `none` = no window on file.
     LabReferenceRangeStatus:
       type: string
       enum:
@@ -33016,9 +33103,9 @@ components:
         - below
         - above
         - unknown
-      description: "Server-computed, NEUTRAL reference-range verdict. `unknown` when the lab reported no usable bounds.
-        Inclusive bounds: a value on the limit reads in-range. The badge that renders this must stay calm and
-        informative — not an alarming red."
+      description: "Server-computed, NEUTRAL reference-range verdict, always against `referenceLow` / `referenceHigh` (the
+        window in force for that reading). `unknown` when no usable bounds are on file. Inclusive bounds: a value on the
+        limit reads in-range. The badge that renders this must stay calm and informative — not an alarming red."
     CreateLabResultResponse:
       type: object
       properties:
@@ -33086,6 +33173,30 @@ components:
           anyOf:
             - type: number
             - type: "null"
+        catalogReferenceLow:
+          anyOf:
+            - type: number
+            - type: "null"
+        catalogReferenceHigh:
+          anyOf:
+            - type: number
+            - type: "null"
+        sourceReferenceLow:
+          anyOf:
+            - type: number
+            - type: "null"
+        sourceReferenceHigh:
+          anyOf:
+            - type: number
+            - type: "null"
+        sourceReferenceText:
+          anyOf:
+            - type: string
+            - type: "null"
+        referenceOrigin:
+          $ref: "#/components/schemas/LabReferenceRangeOrigin"
+        referenceDivergesFromCatalog:
+          type: boolean
         takenAt:
           type: string
         source:
@@ -33110,6 +33221,13 @@ components:
         - unit
         - referenceLow
         - referenceHigh
+        - catalogReferenceLow
+        - catalogReferenceHigh
+        - sourceReferenceLow
+        - sourceReferenceHigh
+        - sourceReferenceText
+        - referenceOrigin
+        - referenceDivergesFromCatalog
         - takenAt
         - source
         - rangeStatus
@@ -33292,6 +33410,14 @@ components:
           anyOf:
             - type: number
             - type: "null"
+        referenceText:
+          anyOf:
+            - type: string
+            - type: "null"
+          description: The reference range EXACTLY as printed on the report, verbatim ("3,5 - 5,0", "< 116", "bis 5,0",
+            "negativ"). `referenceLow` / `referenceHigh` carry the same window reduced to numbers WHEN it reduces to
+            numbers; this field carries it either way, so a window stated in words is not lost between the report and
+            the reading.
         takenAt:
           anyOf:
             - type: string
@@ -33329,6 +33455,7 @@ components:
         - unit
         - referenceLow
         - referenceHigh
+        - referenceText
         - takenAt
         - confidence
         - biomarkerMatch
@@ -33426,6 +33553,34 @@ components:
           anyOf:
             - type: number
             - type: "null"
+        catalogReferenceLow:
+          anyOf:
+            - type: number
+            - type: "null"
+        catalogReferenceHigh:
+          anyOf:
+            - type: number
+            - type: "null"
+        sourceReferenceLow:
+          anyOf:
+            - type: number
+            - type: "null"
+        sourceReferenceHigh:
+          anyOf:
+            - type: number
+            - type: "null"
+        sourceReferenceText:
+          anyOf:
+            - type: string
+            - type: "null"
+        referenceOrigin:
+          type: string
+          enum:
+            - source
+            - catalog
+            - none
+        referenceDivergesFromCatalog:
+          type: boolean
         takenAt:
           type: string
         source:
@@ -33453,6 +33608,13 @@ components:
         - unit
         - referenceLow
         - referenceHigh
+        - catalogReferenceLow
+        - catalogReferenceHigh
+        - sourceReferenceLow
+        - sourceReferenceHigh
+        - sourceReferenceText
+        - referenceOrigin
+        - referenceDivergesFromCatalog
         - takenAt
         - source
         - hasNote
@@ -33460,6 +33622,7 @@ components:
         - createdAt
         - updatedAt
       additionalProperties: false
+      description: A written reading. Its reference window resolves exactly as it does on `/api/labs` — see `LabResult`.
     ListBiomarkersEnvelope:
       type: object
       properties:
diff --git a/messages/de.json b/messages/de.json
index 69655e2de..6565d4a05 100644
--- a/messages/de.json
+++ b/messages/de.json
@@ -281,7 +281,9 @@
     "familyHistoryTitle": "Familienanamnese",
     "familyHistoryColRelationship": "Verwandtschaft",
     "familyHistoryColCondition": "Erkrankung",
-    "familyHistoryColAgeAtOnset": "Alter bei Beginn"
+    "familyHistoryColAgeAtOnset": "Alter bei Beginn",
+    "labsSourceRangeNote": "* Der Referenzbereich stammt aus dem Befund und weicht vom gespeicherten Bereich ab:",
+    "labsCatalogRangeLabel": "gespeicherter Bereich"
   },
   "errorBoundary": {
     "title": "Da ist etwas schiefgelaufen",
@@ -8086,7 +8088,12 @@
       "qualitativePlaceholder": "z. B. negativ",
       "qualNegative": "negativ",
       "qualPositive": "positiv",
-      "qualBorderline": "grenzwertig"
+      "qualBorderline": "grenzwertig",
+      "sourceRange": "Bereich laut Befund",
+      "sourceRangePlaceholder": "z. B. 3,5 - 5,0 oder < 5",
+      "sourceRangeAdd": "+ Bereich aus dem Befund ergänzen",
+      "sourceRangeHint": "Optional. Gilt nur für diesen Wert; dein gespeicherter Bereich bleibt unverändert.",
+      "sourceRangeUnparsed": "Wird so übernommen — daraus ließ sich kein Zahlenbereich lesen."
     },
     "backToLabs": "Zurück zu den Laborwerten",
     "hasNote": "Notiz",
@@ -8117,7 +8124,10 @@
         "90": "90 T",
         "365": "1 J",
         "all": "Alle"
-      }
+      },
+      "sourceRangeLabel": "Befundbereich",
+      "sourceBandLegend": "Zweites Band: der Bereich aus dem Befund vom {date}.",
+      "sourceBandMixed": "Zweites Band: der Bereich aus dem neuesten Befund. Frühere Befunde im Zeitraum nennen andere Bereiche."
     },
     "biomarker": {
       "manageTitle": "Biomarker",
@@ -8292,11 +8302,17 @@
       "fileTooLarge": "Datei ist zu groß (max. 12 MB).",
       "fileType": "Lade ein JPEG, PNG, WebP oder PDF hoch.",
       "extractFailed": "Der Befund konnte nicht gelesen werden. Versuche ein schärferes Foto.",
-      "pdfNeedsAnthropic": "PDF-Scannen benötigt einen Claude-Bildanbieter; lade stattdessen ein Foto hoch."
+      "pdfNeedsAnthropic": "PDF-Scannen benötigt einen Claude-Bildanbieter; lade stattdessen ein Foto hoch.",
+      "refTextLabel": "Bereich wie gedruckt",
+      "refTextPlaceholder": "z. B. 3,5 - 5,0"
     },
     "loadMoreReadings": "Weitere Werte laden",
     "documentsLink": "Befund-Dokumente",
-    "notLinkedYet": "Noch keinem Biomarker zugeordnet"
+    "notLinkedYet": "Noch keinem Biomarker zugeordnet",
+    "sourceRange": {
+      "fromReport": "Befundbereich {range}",
+      "catalogDiffers": "dein Bereich {range}"
+    }
   },
   "modules": {
     "cycle": {
diff --git a/messages/en.json b/messages/en.json
index 412589882..68d644404 100644
--- a/messages/en.json
+++ b/messages/en.json
@@ -281,7 +281,9 @@
     "familyHistoryTitle": "Family history",
     "familyHistoryColRelationship": "Relative",
     "familyHistoryColCondition": "Condition",
-    "familyHistoryColAgeAtOnset": "Age at onset"
+    "familyHistoryColAgeAtOnset": "Age at onset",
+    "labsSourceRangeNote": "* The reference range comes from the report itself and differs from the saved range:",
+    "labsCatalogRangeLabel": "saved range"
   },
   "errorBoundary": {
     "title": "Something went wrong",
@@ -8086,7 +8088,12 @@
       "qualitativePlaceholder": "e.g. negative",
       "qualNegative": "negative",
       "qualPositive": "positive",
-      "qualBorderline": "borderline"
+      "qualBorderline": "borderline",
+      "sourceRange": "Range printed on the report",
+      "sourceRangePlaceholder": "e.g. 3.5 - 5.0 or < 5",
+      "sourceRangeAdd": "+ Add the range from the report",
+      "sourceRangeHint": "Optional. Applies to this reading only; your saved range stays as it is.",
+      "sourceRangeUnparsed": "Kept as written — no numeric range read from it."
     },
     "backToLabs": "Back to lab results",
     "hasNote": "Note",
@@ -8117,7 +8124,10 @@
         "90": "90d",
         "365": "1y",
         "all": "All"
-      }
+      },
+      "sourceRangeLabel": "Report range",
+      "sourceBandLegend": "Second band: the range printed on the report of {date}.",
+      "sourceBandMixed": "Second band: the range printed on the most recent report. Earlier reports in view state different ranges."
     },
     "biomarker": {
       "manageTitle": "Biomarkers",
@@ -8292,11 +8302,17 @@
       "fileTooLarge": "File is too large (max 12 MB).",
       "fileType": "Upload a JPEG, PNG, WebP, or PDF.",
       "extractFailed": "Couldn't read the report. Try a clearer photo.",
-      "pdfNeedsAnthropic": "PDF scanning needs a Claude vision provider; upload a photo instead."
+      "pdfNeedsAnthropic": "PDF scanning needs a Claude vision provider; upload a photo instead.",
+      "refTextLabel": "Range as printed",
+      "refTextPlaceholder": "e.g. 3.5 - 5.0"
     },
     "loadMoreReadings": "Load more readings",
     "documentsLink": "Lab report documents",
-    "notLinkedYet": "Not linked to a biomarker yet"
+    "notLinkedYet": "Not linked to a biomarker yet",
+    "sourceRange": {
+      "fromReport": "Report range {range}",
+      "catalogDiffers": "your range {range}"
+    }
   },
   "modules": {
     "cycle": {
diff --git a/messages/es.json b/messages/es.json
index 5cc45adb6..f0ce9484e 100644
--- a/messages/es.json
+++ b/messages/es.json
@@ -281,7 +281,9 @@
     "familyHistoryTitle": "Antecedentes familiares",
     "familyHistoryColRelationship": "Parentesco",
     "familyHistoryColCondition": "Afección",
-    "familyHistoryColAgeAtOnset": "Edad de inicio"
+    "familyHistoryColAgeAtOnset": "Edad de inicio",
+    "labsSourceRangeNote": "* El rango de referencia procede del propio informe y difiere del rango guardado:",
+    "labsCatalogRangeLabel": "rango guardado"
   },
   "errorBoundary": {
     "title": "Algo ha salido mal",
@@ -8086,7 +8088,12 @@
       "qualitativePlaceholder": "p. ej. negativo",
       "qualNegative": "negativo",
       "qualPositive": "positivo",
-      "qualBorderline": "límite"
+      "qualBorderline": "límite",
+      "sourceRange": "Rango impreso en el informe",
+      "sourceRangePlaceholder": "p. ej. 3,5 - 5,0 o < 5",
+      "sourceRangeAdd": "+ Añadir el rango del informe",
+      "sourceRangeHint": "Opcional. Se aplica solo a esta lectura; tu rango guardado no cambia.",
+      "sourceRangeUnparsed": "Se guarda tal cual: no se pudo leer un rango numérico."
     },
     "backToLabs": "Volver a los resultados",
     "hasNote": "Nota",
@@ -8117,7 +8124,10 @@
         "90": "90 d",
         "365": "1 a",
         "all": "Todo"
-      }
+      },
+      "sourceRangeLabel": "Rango del informe",
+      "sourceBandLegend": "Segunda banda: el rango impreso en el informe del {date}.",
+      "sourceBandMixed": "Segunda banda: el rango impreso en el informe más reciente. Informes anteriores del periodo indican rangos distintos."
     },
     "biomarker": {
       "manageTitle": "Biomarcadores",
@@ -8292,11 +8302,17 @@
       "fileTooLarge": "El archivo es demasiado grande (máx. 12 MB).",
       "fileType": "Sube un JPEG, PNG, WebP o PDF.",
       "extractFailed": "No se pudo leer el informe. Prueba con una foto más nítida.",
-      "pdfNeedsAnthropic": "El escaneo de PDF necesita un proveedor de visión de Claude; sube una foto en su lugar."
+      "pdfNeedsAnthropic": "El escaneo de PDF necesita un proveedor de visión de Claude; sube una foto en su lugar.",
+      "refTextLabel": "Rango tal como aparece",
+      "refTextPlaceholder": "p. ej. 3,5 - 5,0"
     },
     "loadMoreReadings": "Cargar más mediciones",
     "documentsLink": "Documentos de resultados",
-    "notLinkedYet": "Aún no vinculado a un biomarcador"
+    "notLinkedYet": "Aún no vinculado a un biomarcador",
+    "sourceRange": {
+      "fromReport": "Rango del informe {range}",
+      "catalogDiffers": "tu rango {range}"
+    }
   },
   "modules": {
     "cycle": {
diff --git a/messages/fr.json b/messages/fr.json
index 246e2aee0..6ce20efa6 100644
--- a/messages/fr.json
+++ b/messages/fr.json
@@ -281,7 +281,9 @@
     "familyHistoryTitle": "Antécédents familiaux",
     "familyHistoryColRelationship": "Lien de parenté",
     "familyHistoryColCondition": "Affection",
-    "familyHistoryColAgeAtOnset": "Âge au début"
+    "familyHistoryColAgeAtOnset": "Âge au début",
+    "labsSourceRangeNote": "* La plage de référence provient du compte rendu lui-même et diffère de la plage enregistrée :",
+    "labsCatalogRangeLabel": "plage enregistrée"
   },
   "errorBoundary": {
     "title": "Une erreur est survenue",
@@ -8086,7 +8088,12 @@
       "qualitativePlaceholder": "p. ex. négatif",
       "qualNegative": "négatif",
       "qualPositive": "positif",
-      "qualBorderline": "limite"
+      "qualBorderline": "limite",
+      "sourceRange": "Plage imprimée sur le compte rendu",
+      "sourceRangePlaceholder": "p. ex. 3,5 - 5,0 ou < 5",
+      "sourceRangeAdd": "+ Ajouter la plage du compte rendu",
+      "sourceRangeHint": "Facultatif. Ne vaut que pour cette mesure ; votre plage enregistrée reste inchangée.",
+      "sourceRangeUnparsed": "Conservé tel quel : aucune plage numérique n'a pu en être lue."
     },
     "backToLabs": "Retour aux résultats",
     "hasNote": "Note",
@@ -8117,7 +8124,10 @@
         "90": "90 j",
         "365": "1 a",
         "all": "Tout"
-      }
+      },
+      "sourceRangeLabel": "Plage du compte rendu",
+      "sourceBandLegend": "Deuxième bande : la plage imprimée sur le compte rendu du {date}.",
+      "sourceBandMixed": "Deuxième bande : la plage imprimée sur le compte rendu le plus récent. Des comptes rendus antérieurs de la période indiquent d'autres plages."
     },
     "biomarker": {
       "manageTitle": "Biomarqueurs",
@@ -8292,11 +8302,17 @@
       "fileTooLarge": "Le fichier est trop volumineux (max. 12 Mo).",
       "fileType": "Importez un JPEG, PNG, WebP ou PDF.",
       "extractFailed": "Impossible de lire le compte rendu. Essayez une photo plus nette.",
-      "pdfNeedsAnthropic": "Le scan PDF nécessite un fournisseur de vision Claude ; importez plutôt une photo."
+      "pdfNeedsAnthropic": "Le scan PDF nécessite un fournisseur de vision Claude ; importez plutôt une photo.",
+      "refTextLabel": "Plage telle qu'imprimée",
+      "refTextPlaceholder": "p. ex. 3,5 - 5,0"
     },
     "loadMoreReadings": "Charger plus de mesures",
     "documentsLink": "Documents de résultats",
-    "notLinkedYet": "Pas encore lié à un biomarqueur"
+    "notLinkedYet": "Pas encore lié à un biomarqueur",
+    "sourceRange": {
+      "fromReport": "Plage du compte rendu {range}",
+      "catalogDiffers": "votre plage {range}"
+    }
   },
   "modules": {
     "cycle": {
diff --git a/messages/it.json b/messages/it.json
index 6120167d7..f7e60cd97 100644
--- a/messages/it.json
+++ b/messages/it.json
@@ -281,7 +281,9 @@
     "familyHistoryTitle": "Anamnesi familiare",
     "familyHistoryColRelationship": "Parentela",
     "familyHistoryColCondition": "Condizione",
-    "familyHistoryColAgeAtOnset": "Età di esordio"
+    "familyHistoryColAgeAtOnset": "Età di esordio",
+    "labsSourceRangeNote": "* L'intervallo di riferimento proviene dal referto stesso e differisce da quello salvato:",
+    "labsCatalogRangeLabel": "intervallo salvato"
   },
   "errorBoundary": {
     "title": "Qualcosa è andato storto",
@@ -8086,7 +8088,12 @@
       "qualitativePlaceholder": "es. negativo",
       "qualNegative": "negativo",
       "qualPositive": "positivo",
-      "qualBorderline": "borderline"
+      "qualBorderline": "borderline",
+      "sourceRange": "Intervallo stampato sul referto",
+      "sourceRangePlaceholder": "es. 3,5 - 5,0 oppure < 5",
+      "sourceRangeAdd": "+ Aggiungi l'intervallo dal referto",
+      "sourceRangeHint": "Facoltativo. Vale solo per questa misura; l'intervallo salvato resta invariato.",
+      "sourceRangeUnparsed": "Conservato così com'è: non è stato letto alcun intervallo numerico."
     },
     "backToLabs": "Torna ai risultati",
     "hasNote": "Nota",
@@ -8117,7 +8124,10 @@
         "90": "90 g",
         "365": "1 a",
         "all": "Tutto"
-      }
+      },
+      "sourceRangeLabel": "Intervallo del referto",
+      "sourceBandLegend": "Seconda banda: l'intervallo stampato sul referto del {date}.",
+      "sourceBandMixed": "Seconda banda: l'intervallo stampato sul referto più recente. Referti precedenti nel periodo indicano intervalli diversi."
     },
     "biomarker": {
       "manageTitle": "Biomarcatori",
@@ -8292,11 +8302,17 @@
       "fileTooLarge": "Il file è troppo grande (max 12 MB).",
       "fileType": "Carica un JPEG, PNG, WebP o PDF.",
       "extractFailed": "Impossibile leggere il referto. Prova con una foto più nitida.",
-      "pdfNeedsAnthropic": "La scansione PDF richiede un provider di visione Claude; carica invece una foto."
+      "pdfNeedsAnthropic": "La scansione PDF richiede un provider di visione Claude; carica invece una foto.",
+      "refTextLabel": "Intervallo come stampato",
+      "refTextPlaceholder": "es. 3,5 - 5,0"
     },
     "loadMoreReadings": "Carica altre misurazioni",
     "documentsLink": "Documenti dei referti",
-    "notLinkedYet": "Non ancora collegato a un biomarcatore"
+    "notLinkedYet": "Non ancora collegato a un biomarcatore",
+    "sourceRange": {
+      "fromReport": "Intervallo del referto {range}",
+      "catalogDiffers": "il tuo intervallo {range}"
+    }
   },
   "modules": {
     "cycle": {
diff --git a/messages/pl.json b/messages/pl.json
index 007254a17..ba8680481 100644
--- a/messages/pl.json
+++ b/messages/pl.json
@@ -281,7 +281,9 @@
     "familyHistoryTitle": "Wywiad rodzinny",
     "familyHistoryColRelationship": "Pokrewieństwo",
     "familyHistoryColCondition": "Schorzenie",
-    "familyHistoryColAgeAtOnset": "Wiek zachorowania"
+    "familyHistoryColAgeAtOnset": "Wiek zachorowania",
+    "labsSourceRangeNote": "* Zakres referencyjny pochodzi z samego wyniku i różni się od zapisanego zakresu:",
+    "labsCatalogRangeLabel": "zapisany zakres"
   },
   "errorBoundary": {
     "title": "Coś poszło nie tak",
@@ -8086,7 +8088,12 @@
       "qualitativePlaceholder": "np. ujemny",
       "qualNegative": "ujemny",
       "qualPositive": "dodatni",
-      "qualBorderline": "graniczny"
+      "qualBorderline": "graniczny",
+      "sourceRange": "Zakres wydrukowany na wyniku",
+      "sourceRangePlaceholder": "np. 3,5 - 5,0 lub < 5",
+      "sourceRangeAdd": "+ Dodaj zakres z wyniku",
+      "sourceRangeHint": "Opcjonalne. Dotyczy tylko tego pomiaru; zapisany zakres pozostaje bez zmian.",
+      "sourceRangeUnparsed": "Zapisane bez zmian — nie odczytano z tego zakresu liczbowego."
     },
     "backToLabs": "Wróć do wyników",
     "hasNote": "Notatka",
@@ -8117,7 +8124,10 @@
         "90": "90 d",
         "365": "1 r",
         "all": "Wszystko"
-      }
+      },
+      "sourceRangeLabel": "Zakres z wyniku",
+      "sourceBandLegend": "Drugie pasmo: zakres wydrukowany na wyniku z {date}.",
+      "sourceBandMixed": "Drugie pasmo: zakres z najnowszego wyniku. Wcześniejsze wyniki w tym okresie podają inne zakresy."
     },
     "biomarker": {
       "manageTitle": "Biomarkery",
@@ -8292,11 +8302,17 @@
       "fileTooLarge": "Plik jest za duży (maks. 12 MB).",
       "fileType": "Prześlij plik JPEG, PNG, WebP lub PDF.",
       "extractFailed": "Nie udało się odczytać wyniku. Spróbuj wyraźniejszego zdjęcia.",
-      "pdfNeedsAnthropic": "Skanowanie PDF wymaga dostawcy wizji Claude; prześlij zamiast tego zdjęcie."
+      "pdfNeedsAnthropic": "Skanowanie PDF wymaga dostawcy wizji Claude; prześlij zamiast tego zdjęcie.",
+      "refTextLabel": "Zakres tak jak wydrukowano",
+      "refTextPlaceholder": "np. 3,5 - 5,0"
     },
     "loadMoreReadings": "Wczytaj więcej pomiarów",
     "documentsLink": "Dokumenty wyników badań",
-    "notLinkedYet": "Jeszcze niepowiązane z biomarkerem"
+    "notLinkedYet": "Jeszcze niepowiązane z biomarkerem",
+    "sourceRange": {
+      "fromReport": "Zakres z wyniku {range}",
+      "catalogDiffers": "twój zakres {range}"
+    }
   },
   "modules": {
     "cycle": {
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 92dc14bec..4f5efaea5 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -7,6 +7,7 @@ settings:
 overrides:
   dompurify@<=3.4.10: ^3.4.11
   postcss@<8.5.10: ^8.5.10
+  nanoid@<3.3.17: ^3.3.17
   '@hono/node-server@<1.19.13': ^1.19.13
   hono@<4.12.25: ^4.12.25
   picomatch@<4.0.4: ^4.0.4
@@ -5556,13 +5557,8 @@ packages:
   nan@2.27.0:
     resolution: {integrity: sha512-hC+0LidcL3XE4rp1C4H54KujgXKzbfyTngZTwBByQxsOxCEKZT0MPQ4hOKUH2jU1OYstqdDH4onyHPDzcV0XdQ==}
 
-  nanoid@3.3.12:
-    resolution: {integrity: sha512-ZB9RH/39qpq5Vu6Y+NmUaFhQR6pp+M2Xt76XBnEwDaGcVAqhlvxrl3B2bKS5D3NH3QR76v3aSrKaF/Kiy7lEtQ==}
-    engines: {node: ^10 || ^12 || ^13.7 || ^14 || >=15.0.1}
-    hasBin: true
-
-  nanoid@3.3.16:
-    resolution: {integrity: sha512-bzlKTyNJ7+LdGIIwy8ijFpIqEQIvafahV7eYykJ8Cvh42EdJeODoJ6gUJXpQJvej1BddH8OqTXZNE/KfbWAu8Q==}
+  nanoid@3.3.17:
+    resolution: {integrity: sha512-xQLf0A3HOMlgHq0n247/LRuAOYmB7dXJ/DvAxGvsSBij45XtBSmQycu+F8ODbHwns/XyFZagyL1+J0Offw1E0g==}
     engines: {node: ^10 || ^12 || ^13.7 || ^14 || >=15.0.1}
     hasBin: true
 
@@ -12636,9 +12632,7 @@ snapshots:
   nan@2.27.0:
     optional: true
 
-  nanoid@3.3.12: {}
-
-  nanoid@3.3.16: {}
+  nanoid@3.3.17: {}
 
   napi-postinstall@0.3.4: {}
 
@@ -13045,19 +13039,19 @@ snapshots:
 
   postcss@8.5.14:
     dependencies:
-      nanoid: 3.3.12
+      nanoid: 3.3.17
       picocolors: 1.1.1
       source-map-js: 1.2.1
 
   postcss@8.5.20:
     dependencies:
-      nanoid: 3.3.16
+      nanoid: 3.3.17
       picocolors: 1.1.1
       source-map-js: 1.2.1
 
   postcss@8.5.25:
     dependencies:
-      nanoid: 3.3.16
+      nanoid: 3.3.17
       picocolors: 1.1.1
       source-map-js: 1.2.1
 
diff --git a/pnpm-workspace.yaml b/pnpm-workspace.yaml
index c7fabca7c..3fa8ec2d3 100644
--- a/pnpm-workspace.yaml
+++ b/pnpm-workspace.yaml
@@ -1,6 +1,7 @@
 overrides:
   "dompurify@<=3.4.10": "^3.4.11"
   "postcss@<8.5.10": "^8.5.10"
+  "nanoid@<3.3.17": "^3.3.17"
   "@hono/node-server@<1.19.13": "^1.19.13"
   "hono@<4.12.25": "^4.12.25"
   "picomatch@<4.0.4": "^4.0.4"
diff --git a/prisma/migrations/0303_lab_source_reference_range/migration.sql b/prisma/migrations/0303_lab_source_reference_range/migration.sql
new file mode 100644
index 000000000..d4f6644c1
--- /dev/null
+++ b/prisma/migrations/0303_lab_source_reference_range/migration.sql
@@ -0,0 +1,14 @@
+-- Per-reading source reference range on a lab result.
+--
+-- A lab report prints the window its own method and device produce, right
+-- beside the value, and that window is what a physician evaluates against.
+-- Until now the document reading pulled the value and dropped the range.
+-- These three columns carry it: the derived numeric bounds where the printed
+-- string yields them, plus the report's verbatim string, which is stored
+-- whether or not it parsed. Nothing is backfilled — an existing row genuinely
+-- has no source range on file and stays NULL.
+
+ALTER TABLE "lab_results"
+  ADD COLUMN "source_reference_low" DOUBLE PRECISION,
+  ADD COLUMN "source_reference_high" DOUBLE PRECISION,
+  ADD COLUMN "source_reference_text" TEXT;
diff --git a/prisma/schema.prisma b/prisma/schema.prisma
index ffc9a4a14..affc5e70c 100644
--- a/prisma/schema.prisma
+++ b/prisma/schema.prisma
@@ -5057,9 +5057,41 @@ model LabResult {
   /// reference bounds + range verdict are meaningless for a qualitative row.
   valueText     String?   @map("value_text")
   unit          String
-  /// Optional reference-range bounds as reported by the lab.
+  /// Reference-range bounds stamped onto the row at write time. Despite the
+  /// name these are NOT the lab's printed range: since v1.18.1 every write
+  /// path copies the linked `Biomarker`'s `lowerBound` / `upperBound` here as
+  /// historical truth, so a later catalog edit does not silently rewrite a
+  /// past reading. The range the LAB printed lives in `sourceReference*`.
   referenceLow  Float?    @map("reference_low")
   referenceHigh Float?    @map("reference_high")
+
+  /// The reference range as PRINTED ON THE SOURCE REPORT for this one reading.
+  ///
+  /// Labs run different methods on different devices, so the window a
+  /// physician evaluates against is the one printed beside the value on that
+  /// report — not a catalog band that averages every lab. These three columns
+  /// carry it: the parsed numeric bounds where a bound could be derived, and
+  /// `sourceReferenceText` as the report's own verbatim string ("< 5",
+  /// "bis 5,0", "negativ", "siehe Befund"). The text is kept whenever the
+  /// source printed one, parseable or not — absence reads as absence, and a
+  /// window that could not be derived is never invented.
+  ///
+  /// Precedence: for a single reading the source bounds win over the catalog
+  /// band; the catalog stays the net for readings that carry no source range.
+  /// `resolveEffectiveReferenceRange` in `src/lib/labs/reference-range.ts` is
+  /// the one place that rule is expressed, and every surface that judges a
+  /// reading routes through it.
+  ///
+  /// Plaintext, not `*Encrypted`: that suffix marks user prose (`noteEncrypted`
+  /// here, `Biomarker.contextEncrypted` next door). This is a structured
+  /// lab-report field of exactly the class of the plaintext `analyte` / `unit`
+  /// / `value` / `valueText` columns beside it — `valueText` already carries
+  /// the actual clinical RESULT ("positiv") in the clear, so encrypting the
+  /// window that result is judged against would protect strictly less while
+  /// making the column unreadable to the SQL the read paths run.
+  sourceReferenceLow  Float?  @map("source_reference_low")
+  sourceReferenceHigh Float?  @map("source_reference_high")
+  sourceReferenceText String? @map("source_reference_text")
   /// When the sample was taken (UTC instant; wall-clock anchoring is the
   /// reader's concern per the schema's UTC-only convention).
   takenAt       DateTime  @map("taken_at")
diff --git a/scripts/diagnose-implausible-measurements.ts b/scripts/diagnose-implausible-measurements.ts
new file mode 100644
index 000000000..0be518a26
--- /dev/null
+++ b/scripts/diagnose-implausible-measurements.ts
@@ -0,0 +1,150 @@
+/**
+ * Read-only diagnostic for stored measurement rows outside the app's own
+ * declared plausibility domain.
+ *
+ * `VALUE_RANGES` in `@/lib/validations/measurement` is the band the
+ * application says a metric can occupy. Every path a person can drive has
+ * always enforced it; the provider sync writers did not, so rows the
+ * application itself calls impossible reached the table — and every mean,
+ * median and personal band built from them inherited the impossibility. The
+ * writers enforce it now, which stops new rows landing. It says nothing about
+ * the rows already there.
+ *
+ * This reports them and repairs nothing. What to do with a stored impossible
+ * row is a judgement the data cannot make: a pulse of 55 million is plainly a
+ * decode slip and a candidate for deletion, while a weight of 0.9 kg might be
+ * a neonatal record on a shared scale, or a unit mix-up, or a real reading the
+ * band is simply too narrow for. Deleting somebody's health record on a
+ * heuristic is not a thing a script gets to decide.
+ *
+ * Output is aggregate: one line per (metric, source) bucket with the row
+ * count, the number of distinct records affected, the observed extremes, and
+ * the window they fall in. Individual readings are not printed — the bucket
+ * plus the metric's own declared bound is what a decision needs, and a log
+ * file full of somebody's vitals is not.
+ *
+ * Run (inside the app container, which has DATABASE_URL):
+ *   pnpm dlx tsx scripts/diagnose-implausible-measurements.ts
+ */
+import "dotenv/config";
+
+import { prisma } from "@/lib/db";
+import { VALUE_RANGES } from "@/lib/validations/measurement";
+
+interface BucketRow {
+  type: string;
+  source: string;
+  row_count: bigint;
+  record_count: bigint;
+  min_value: number;
+  max_value: number;
+  first_at: Date;
+  last_at: Date;
+  tombstoned: bigint;
+}
+
+function ymd(date: Date): string {
+  return date.toISOString().slice(0, 10);
+}
+
+async function main(): Promise<void> {
+  const types = Object.keys(VALUE_RANGES).sort();
+  const mins = types.map((t) => VALUE_RANGES[t]!.min);
+  const maxes = types.map((t) => VALUE_RANGES[t]!.max);
+
+  // The band table rides in as three parallel bound arrays rather than a
+  // spliced VALUES list, so the query carries no interpolated text at all.
+  // `value <> value` is the NaN probe: a double-precision column can hold one,
+  // and it compares false against every bound including itself.
+  const buckets = await prisma.$queryRaw<BucketRow[]>`
+    WITH bands(type, min_value, max_value) AS (
+      SELECT * FROM unnest(
+        ${types}::text[],
+        ${mins}::double precision[],
+        ${maxes}::double precision[]
+      )
+    )
+    SELECT
+      m."type"::text                                        AS type,
+      m."source"::text                                      AS source,
+      COUNT(*)::bigint                                      AS row_count,
+      COUNT(DISTINCT m."user_id")::bigint                   AS record_count,
+      MIN(m."value")                                        AS min_value,
+      MAX(m."value")                                        AS max_value,
+      MIN(m."measured_at")                                  AS first_at,
+      MAX(m."measured_at")                                  AS last_at,
+      COUNT(*) FILTER (WHERE m."deleted_at" IS NOT NULL)::bigint AS tombstoned
+    FROM "measurements" m
+    JOIN bands b ON b."type" = m."type"::text
+    WHERE m."value" < b.min_value
+       OR m."value" > b.max_value
+       OR m."value" <> m."value"
+    GROUP BY m."type", m."source"
+    ORDER BY COUNT(*) DESC, m."type"::text ASC, m."source"::text ASC
+  `;
+
+  if (buckets.length === 0) {
+    console.log(
+      `Every stored measurement sits inside its metric's declared range ` +
+        `(${types.length} metric bands checked). Nothing to review.`,
+    );
+    return;
+  }
+
+  const totalRows = buckets.reduce((sum, b) => sum + Number(b.row_count), 0);
+  const affectedTypes = new Set(buckets.map((b) => b.type));
+  const affectedSources = new Set(buckets.map((b) => b.source));
+
+  console.log(
+    `${totalRows} stored row(s) sit outside the declared plausibility band, ` +
+      `across ${affectedTypes.size} metric(s) and ${affectedSources.size} source(s).\n` +
+      `Nothing below is modified. Each line is a (metric, source) bucket; the ` +
+      `band is the metric's own declared domain.\n`,
+  );
+
+  // Group by metric so the declared band is stated once per heading, and rank
+  // the metrics by how much of the problem each one is. The query's own
+  // ordering already ranks the sources inside a metric.
+  const byType = new Map<string, BucketRow[]>();
+  for (const bucket of buckets) {
+    const bucketsForType = byType.get(bucket.type);
+    if (bucketsForType) bucketsForType.push(bucket);
+    else byType.set(bucket.type, [bucket]);
+  }
+  const ranked = [...byType.entries()].sort(
+    (a, b) =>
+      b[1].reduce((sum, x) => sum + Number(x.row_count), 0) -
+      a[1].reduce((sum, x) => sum + Number(x.row_count), 0),
+  );
+
+  for (const [type, rows] of ranked) {
+    const band = VALUE_RANGES[type]!;
+    console.log(`${type} — declared band ${band.min}…${band.max}`);
+    for (const bucket of rows) {
+      const live = Number(bucket.row_count) - Number(bucket.tombstoned);
+      console.log(
+        `  ${bucket.source.padEnd(14)} ` +
+          `${String(bucket.row_count).padStart(7)} row(s) ` +
+          `(${live} live, ${bucket.tombstoned} tombstoned) ` +
+          `across ${bucket.record_count} record(s) — ` +
+          `observed ${bucket.min_value}…${bucket.max_value}, ` +
+          `${ymd(bucket.first_at)} → ${ymd(bucket.last_at)}`,
+      );
+    }
+  }
+
+  console.log(
+    `\nThe sync writers refuse these values now, so the population above is ` +
+      `closed unless a writer without the gate is still in play. Removing a ` +
+      `row is a maintainer decision, per bucket.`,
+  );
+}
+
+main()
+  .catch((err) => {
+    console.error(err);
+    process.exitCode = 1;
+  })
+  .finally(() => {
+    void prisma.$disconnect();
+  });
diff --git a/src/__tests__/measurement-write-plausibility-guard.test.ts b/src/__tests__/measurement-write-plausibility-guard.test.ts
new file mode 100644
index 000000000..88fbafee2
--- /dev/null
+++ b/src/__tests__/measurement-write-plausibility-guard.test.ts
@@ -0,0 +1,200 @@
+/**
+ * Structural guard on the measurement ingest boundary.
+ *
+ * `VALUE_RANGES` is the band the application declares a metric can occupy.
+ * Every path a person can drive enforced it from the start; the provider sync
+ * writers never did, and nothing noticed, because each writer is correct on
+ * its own terms — it wrote what the remote sent. The gap was only visible from
+ * above, by listing every writer at once and asking which of them had ever
+ * been told about the band.
+ *
+ * So the list lives here. Every file that writes a `Measurement` row is
+ * enumerated with the reason it is allowed to, and the guard fails when the
+ * discovered set stops matching. A provider added tomorrow lands a file that
+ * is not in the map and has to answer the question before it can ship.
+ *
+ * This is a tripwire, not a proof. It cannot show a disposition is the right
+ * one — only that nobody added a writer without writing down which gate covers
+ * it. A reviewer who waves through a bogus `derived` label defeats it, and no
+ * test substitutes for that review.
+ */
+import { describe, it, expect } from "vitest";
+import { readFileSync } from "node:fs";
+import { join } from "node:path";
+
+import { walkSourceFiles } from "./helpers/source-files";
+
+const SRC = join(process.cwd(), "src");
+
+/** The gate module every provider-fed writer has to reach. */
+const GATE_MODULE = "@/lib/measurements/plausibility-gate";
+/** The predicate every person-driven write path has always used. */
+const VALIDATOR = "validateMeasurementRange";
+
+/**
+ * How a writer satisfies the plausibility domain.
+ *
+ * - `gate` — provider-fed; must reach {@link GATE_MODULE} itself.
+ * - `validator` — person-driven; must call {@link VALIDATOR} itself.
+ * - `upstream` — validated in a named module before the row is built; the
+ *   named module is checked, so the label cannot be a shrug.
+ * - `derived` — the value is arithmetic over rows already in the table, not a
+ *   number from outside. Gating here would drop a consolidation of data that
+ *   IS present, which is a different failure from admitting one that is not.
+ * - `literal` — the written value is a constant in the file, so no external
+ *   number can reach the column.
+ * - `restore` — replays the record's own backup verbatim. Fidelity is the
+ *   contract; a restore that silently dropped rows would be the worse bug,
+ *   and the diagnostic script is how a stored impossible row gets found.
+ */
+type Disposition =
+  | { kind: "gate" }
+  | { kind: "validator" }
+  | { kind: "upstream"; validatedIn: string }
+  | { kind: "derived"; why: string }
+  | { kind: "literal"; why: string }
+  | { kind: "restore"; why: string };
+
+const WRITERS: Record<string, Disposition> = {
+  // ── Provider sync writers, gated ──────────────────────────────────────
+  "lib/withings/sync.ts": { kind: "gate" },
+  "lib/withings/sync-activity.ts": { kind: "gate" },
+  "lib/fitbit/sync-core.ts": { kind: "gate" },
+  "lib/google-health/sync-core.ts": { kind: "gate" },
+  "lib/nightscout/sync.ts": { kind: "gate" },
+  // The shared identity seam. Polar, Oura, WHOOP, the Withings sleep leg,
+  // the Apple export importer and the batch endpoint all write through it,
+  // so the gate here is what makes a new provider fail closed.
+  "lib/measurements/reconcile-external-measurement.ts": { kind: "gate" },
+
+  // ── Person-driven write paths, validated ──────────────────────────────
+  "app/api/measurements/route.ts": {
+    kind: "upstream",
+    validatedIn: "lib/validations/measurement.ts",
+  },
+  "app/api/import/route.ts": { kind: "validator" },
+  "lib/mcp/writes.ts": { kind: "validator" },
+  "lib/measurements/create-from-telegram.ts": { kind: "validator" },
+  "lib/measurements/import-apple-health-export.ts": { kind: "validator" },
+  "app/api/import/csv/route.ts": {
+    kind: "upstream",
+    validatedIn: "lib/import/csv-measurements.ts",
+  },
+
+  // ── Fixed values ──────────────────────────────────────────────────────
+  "lib/withings/sync-ecg.ts": {
+    kind: "literal",
+    why: "an ECG row carries value 1 — the file's own constant, never a provider number",
+  },
+  "app/api/mental-health/assessments/route.ts": {
+    kind: "literal",
+    why: "the questionnaire score is summed from Zod-bounded item answers",
+  },
+  "lib/insights/score-row.ts": {
+    kind: "literal",
+    why: "the health score is computed in-app on a closed 0-100 scale",
+  },
+
+  // ── Derived from rows already stored ──────────────────────────────────
+  "lib/measurements/consolidate-daily-mean.ts": {
+    kind: "derived",
+    why: "writes the mean of the day's own stored rows",
+  },
+  "lib/measurements/consolidate-legacy-steps.ts": {
+    kind: "derived",
+    why: "folds stored per-sample step rows into the day's canonical row",
+  },
+  "lib/measurements/dense-intraday-retention.ts": {
+    kind: "derived",
+    why: "rebuilds hourly buckets from stored per-sample rows",
+  },
+  "lib/measurements/drain-per-sample-cumulative.ts": {
+    kind: "derived",
+    why: "reduces stored cumulative per-sample rows to one daily total",
+  },
+
+  // ── Restore ───────────────────────────────────────────────────────────
+  "app/api/admin/backups/[id]/restore/route.ts": {
+    kind: "restore",
+    why: "replays the record's own export; dropping rows would break the restore contract",
+  },
+};
+
+/**
+ * Any Prisma client handle followed by a measurement write. Whitespace- and
+ * handle-tolerant on purpose: the earlier generation of this repo's guards
+ * demanded a literal `prisma.x.findUnique(` and went green because it matched
+ * nothing, not because nothing was there. The transaction handles in use are
+ * `tx` and `pc`; a future one is caught by the `[A-Za-z_$][\w$]*` head.
+ */
+const MEASUREMENT_WRITE =
+  /[A-Za-z_$][\w$]*\s*\.\s*measurement\s*\.\s*(create|createMany|createManyAndReturn|upsert)\s*\(/;
+
+function sourceFiles(): string[] {
+  return walkSourceFiles(SRC, { floor: 3000 })
+    .filter((p) => !p.startsWith("generated/"))
+    .filter((p) => !p.includes("__tests__"))
+    .filter((p) => !p.endsWith(".test.ts") && !p.endsWith(".test.tsx"))
+    .sort();
+}
+
+function read(rel: string): string {
+  return readFileSync(join(SRC, rel), "utf8");
+}
+
+function discoveredWriters(): string[] {
+  return sourceFiles().filter((rel) => MEASUREMENT_WRITE.test(read(rel)));
+}
+
+describe("every measurement writer declares how it meets the plausibility domain", () => {
+  it("finds the writers at all — an empty sweep is a broken guard, not a clean repo", () => {
+    // The map is the claim; this asserts the matcher can still see the
+    // population it describes. A regex that silently stops matching would
+    // otherwise turn every check below into a tautology.
+    expect(discoveredWriters().length).toBeGreaterThanOrEqual(15);
+  });
+
+  it("the discovered writer set matches the declared map exactly", () => {
+    expect(discoveredWriters()).toEqual(Object.keys(WRITERS).sort());
+  });
+
+  it("every provider-fed writer reaches the gate module", () => {
+    const gated = Object.entries(WRITERS)
+      .filter(([, d]) => d.kind === "gate")
+      .map(([rel]) => rel);
+    expect(gated.length).toBeGreaterThanOrEqual(6);
+    for (const rel of gated) {
+      expect(read(rel), `${rel} must import ${GATE_MODULE}`).toContain(
+        GATE_MODULE,
+      );
+    }
+  });
+
+  it("every person-driven writer calls the range validator", () => {
+    for (const [rel, disposition] of Object.entries(WRITERS)) {
+      if (disposition.kind === "validator") {
+        expect(read(rel), `${rel} must call ${VALIDATOR}`).toContain(VALIDATOR);
+      }
+      if (disposition.kind === "upstream") {
+        expect(
+          read(disposition.validatedIn),
+          `${disposition.validatedIn} must call ${VALIDATOR} on behalf of ${rel}`,
+        ).toContain(VALIDATOR);
+      }
+    }
+  });
+
+  it("the exempt writers carry a written reason", () => {
+    for (const [rel, disposition] of Object.entries(WRITERS)) {
+      if (
+        disposition.kind === "derived" ||
+        disposition.kind === "literal" ||
+        disposition.kind === "restore"
+      ) {
+        expect(disposition.why.length, `${rel} needs a reason`).toBeGreaterThan(
+          20,
+        );
+      }
+    }
+  });
+});
diff --git a/src/__tests__/written-outcome-response-consumer-guard.test.ts b/src/__tests__/written-outcome-response-consumer-guard.test.ts
index 904107571..335b152f5 100644
--- a/src/__tests__/written-outcome-response-consumer-guard.test.ts
+++ b/src/__tests__/written-outcome-response-consumer-guard.test.ts
@@ -724,6 +724,13 @@ const OCR_EXCEPTIONS: Readonly<Record<string, string>> = {
   "inserted.unit": OCR_ROW_EXCEPTION,
   "inserted.referenceLow": OCR_ROW_EXCEPTION,
   "inserted.referenceHigh": OCR_ROW_EXCEPTION,
+  "inserted.catalogReferenceLow": OCR_ROW_EXCEPTION,
+  "inserted.catalogReferenceHigh": OCR_ROW_EXCEPTION,
+  "inserted.sourceReferenceLow": OCR_ROW_EXCEPTION,
+  "inserted.sourceReferenceHigh": OCR_ROW_EXCEPTION,
+  "inserted.sourceReferenceText": OCR_ROW_EXCEPTION,
+  "inserted.referenceOrigin": OCR_ROW_EXCEPTION,
+  "inserted.referenceDivergesFromCatalog": OCR_ROW_EXCEPTION,
   "inserted.takenAt": OCR_ROW_EXCEPTION,
   "inserted.source": OCR_ROW_EXCEPTION,
   "inserted.hasNote": OCR_ROW_EXCEPTION,
diff --git a/src/app/api/admin/backups/[id]/restore/route.ts b/src/app/api/admin/backups/[id]/restore/route.ts
index 7a3956b06..a6196cf0c 100644
--- a/src/app/api/admin/backups/[id]/restore/route.ts
+++ b/src/app/api/admin/backups/[id]/restore/route.ts
@@ -980,6 +980,9 @@ const handler = apiHandler(
                 unit: lab.unit,
                 referenceLow: lab.referenceLow ?? null,
                 referenceHigh: lab.referenceHigh ?? null,
+                sourceReferenceLow: lab.sourceReferenceLow ?? null,
+                sourceReferenceHigh: lab.sourceReferenceHigh ?? null,
+                sourceReferenceText: lab.sourceReferenceText ?? null,
                 takenAt: new Date(lab.takenAt),
                 source: lab.source,
                 noteEncrypted:
diff --git a/src/app/api/documents/inbound/[id]/facts/[factId]/route.ts b/src/app/api/documents/inbound/[id]/facts/[factId]/route.ts
index 042b1387e..498a7ce25 100644
--- a/src/app/api/documents/inbound/[id]/facts/[factId]/route.ts
+++ b/src/app/api/documents/inbound/[id]/facts/[factId]/route.ts
@@ -57,6 +57,7 @@ function editToFactData(edit: InboundFactEdit): FactData {
       unit: edit.unit ?? null,
       referenceLow: edit.referenceLow ?? null,
       referenceHigh: edit.referenceHigh ?? null,
+      referenceText: edit.referenceText ?? null,
       effectiveDate: edit.effectiveDate ?? null,
     };
     return data;
diff --git a/src/app/api/insights/labs-changes/route.ts b/src/app/api/insights/labs-changes/route.ts
index 452af57da..ddfde9972 100644
--- a/src/app/api/insights/labs-changes/route.ts
+++ b/src/app/api/insights/labs-changes/route.ts
@@ -46,6 +46,9 @@ export const GET = apiHandler(async () => {
       value: true,
       referenceLow: true,
       referenceHigh: true,
+      sourceReferenceLow: true,
+      sourceReferenceHigh: true,
+      sourceReferenceText: true,
       takenAt: true,
     },
     orderBy: { takenAt: "desc" },
@@ -58,6 +61,9 @@ export const GET = apiHandler(async () => {
       value: r.value as number,
       referenceLow: r.referenceLow,
       referenceHigh: r.referenceHigh,
+      sourceReferenceLow: r.sourceReferenceLow,
+      sourceReferenceHigh: r.sourceReferenceHigh,
+      sourceReferenceText: r.sourceReferenceText,
       takenAt: r.takenAt,
     })),
   );
diff --git a/src/app/api/labs/[id]/route.ts b/src/app/api/labs/[id]/route.ts
index d143259fb..34afa72a7 100644
--- a/src/app/api/labs/[id]/route.ts
+++ b/src/app/api/labs/[id]/route.ts
@@ -143,6 +143,12 @@ export const PUT = apiHandler(
     // historical columns the serialiser ignores. Reject the attempt with a
     // 422 rather than silently no-op, so the client never believes an edit
     // landed. Edit such fields on the Biomarker itself instead.
+    //
+    // `sourceReference*` is deliberately NOT on that list. The catalog band is
+    // a property of the marker; the source window is a property of THIS
+    // reading — it is what one report printed beside one value — so it is
+    // editable on a linked row and there is nothing on the biomarker to edit
+    // it on instead.
     const isLinked = existing.biomarkerId !== null;
     if (
       isLinked &&
@@ -194,6 +200,15 @@ export const PUT = apiHandler(
     if (d.unit !== undefined) data.unit = d.unit;
     if (d.referenceLow !== undefined) data.referenceLow = d.referenceLow;
     if (d.referenceHigh !== undefined) data.referenceHigh = d.referenceHigh;
+    if (d.sourceReferenceLow !== undefined) {
+      data.sourceReferenceLow = d.sourceReferenceLow;
+    }
+    if (d.sourceReferenceHigh !== undefined) {
+      data.sourceReferenceHigh = d.sourceReferenceHigh;
+    }
+    if (d.sourceReferenceText !== undefined) {
+      data.sourceReferenceText = d.sourceReferenceText;
+    }
     if (d.takenAt !== undefined) data.takenAt = d.takenAt;
 
     // Inverted-range guard for a PARTIAL bound update. The schema-level
@@ -212,6 +227,20 @@ export const PUT = apiHandler(
         errorCode: "labs.update.referenceRangeInvalid",
       });
     }
+    // The same partial-update hole exists on the source window, and closes the
+    // same way.
+    if (
+      isInvertedRange(
+        effectiveBound(d.sourceReferenceLow, existing.sourceReferenceLow),
+        effectiveBound(d.sourceReferenceHigh, existing.sourceReferenceHigh),
+      )
+    ) {
+      return apiError(
+        "sourceReferenceLow must not exceed sourceReferenceHigh",
+        422,
+        { errorCode: "labs.update.sourceReferenceRangeInvalid" },
+      );
+    }
     if (d.note !== undefined) {
       data.noteEncrypted = d.note ? encryptNoteToBytes(d.note) : null;
     }
@@ -239,6 +268,9 @@ export const PUT = apiHandler(
             panel: existing.panel,
             referenceLow: existing.referenceLow,
             referenceHigh: existing.referenceHigh,
+            sourceReferenceLow: existing.sourceReferenceLow,
+            sourceReferenceHigh: existing.sourceReferenceHigh,
+            sourceReferenceText: existing.sourceReferenceText,
             takenAt: existing.takenAt,
           },
           after: {
@@ -249,6 +281,9 @@ export const PUT = apiHandler(
             panel: updated.panel,
             referenceLow: updated.referenceLow,
             referenceHigh: updated.referenceHigh,
+            sourceReferenceLow: updated.sourceReferenceLow,
+            sourceReferenceHigh: updated.sourceReferenceHigh,
+            sourceReferenceText: updated.sourceReferenceText,
             takenAt: updated.takenAt,
           },
           redacted: d.note !== undefined ? ["note"] : [],
diff --git a/src/app/api/labs/ocr/commit/route.ts b/src/app/api/labs/ocr/commit/route.ts
index d6bd0b431..b8700562e 100644
--- a/src/app/api/labs/ocr/commit/route.ts
+++ b/src/app/api/labs/ocr/commit/route.ts
@@ -33,6 +33,7 @@ import { withIdempotency } from "@/lib/idempotency";
 import { enqueueReminderSatisfy } from "@/lib/jobs/reminder-satisfy";
 import { emitDataArrival } from "@/lib/arrivals/emit-shared";
 import { resolveOrMintBiomarker } from "@/lib/labs/biomarker-store";
+import { parseReferenceRange } from "@/lib/labs/parse-reference-range";
 import { serialiseLabResult } from "@/lib/labs/serialise";
 import {
   linkOcrLabsToVaultDocument,
@@ -151,12 +152,19 @@ async function commitOcrRows(request: NextRequest) {
     }
 
     const isQualitative = row.valueText !== undefined;
+    // The window the scan read off the report. The confirmed numeric bounds
+    // win over a re-parse of the string (the human may have corrected them on
+    // the review screen); the string rides along either way.
+    const printed = parseReferenceRange(row.referenceText, row.unit);
+    const sourceLow = row.referenceLow ?? printed?.low ?? null;
+    const sourceHigh = row.referenceHigh ?? printed?.high ?? null;
+    const sourceText = printed?.text ?? null;
     const biomarker = await resolveOrMintBiomarker(user.id, {
       analyte: row.analyte,
       // A qualitative reading has no numeric unit / range.
       unit: isQualitative ? (row.unit ?? "") : (row.unit as string),
-      referenceLow: isQualitative ? null : (row.referenceLow ?? null),
-      referenceHigh: isQualitative ? null : (row.referenceHigh ?? null),
+      referenceLow: isQualitative ? null : sourceLow,
+      referenceHigh: isQualitative ? null : sourceHigh,
       panel: row.panel ?? null,
     });
 
@@ -173,6 +181,9 @@ async function commitOcrRows(request: NextRequest) {
         unit: biomarker.unit,
         referenceLow: biomarker.lowerBound,
         referenceHigh: biomarker.upperBound,
+        sourceReferenceLow: isQualitative ? null : sourceLow,
+        sourceReferenceHigh: isQualitative ? null : sourceHigh,
+        sourceReferenceText: isQualitative ? null : sourceText,
         takenAt: row.takenAt,
         source: "OCR",
         noteEncrypted: null,
diff --git a/src/app/api/labs/route.ts b/src/app/api/labs/route.ts
index 1ab53c06c..60e325499 100644
--- a/src/app/api/labs/route.ts
+++ b/src/app/api/labs/route.ts
@@ -184,6 +184,9 @@ async function postLabResult(request: NextRequest) {
     unit,
     referenceLow,
     referenceHigh,
+    sourceReferenceLow,
+    sourceReferenceHigh,
+    sourceReferenceText,
     takenAt,
     note,
     source,
@@ -248,6 +251,13 @@ async function postLabResult(request: NextRequest) {
       unit: biomarker.unit,
       referenceLow: biomarker.lowerBound,
       referenceHigh: biomarker.upperBound,
+      // The window this reading's own report printed, kept beside the catalog
+      // stamp rather than folded into it: it governs THIS reading's verdict,
+      // and the catalog band stays the net for every reading without one. A
+      // qualitative reading has no window to record.
+      sourceReferenceLow: isQualitative ? null : (sourceReferenceLow ?? null),
+      sourceReferenceHigh: isQualitative ? null : (sourceReferenceHigh ?? null),
+      sourceReferenceText: isQualitative ? null : (sourceReferenceText ?? null),
       takenAt,
       // v1.25 (iOS #36) — provenance: the on-device-OCR path posts
       // `source: "OCR"`; an omitted field stays "MANUAL" so the legacy
@@ -258,6 +268,7 @@ async function postLabResult(request: NextRequest) {
     },
   });
   invalidateUserHealthScore(user.id);
+  const dto = serialiseLabResult(created, biomarker);
 
   await auditLog("labResult.create", {
     userId: user.id,
@@ -275,6 +286,9 @@ async function postLabResult(request: NextRequest) {
       structured: biomarkerId !== undefined,
       // v1.25 (iOS #36) — provenance of the reading ("MANUAL" | "OCR").
       source: source ?? "MANUAL",
+      // Which window governs this reading's verdict, so a dashboard can see
+      // how often a report's own range displaces the catalog band.
+      referenceOrigin: dto.referenceOrigin,
     },
   });
 
@@ -298,5 +312,5 @@ async function postLabResult(request: NextRequest) {
     source: "manual",
   }).catch(() => {});
 
-  return apiSuccess(serialiseLabResult(created, biomarker), 201);
+  return apiSuccess(dto, 201);
 }
diff --git a/src/app/api/measurements/batch/route.ts b/src/app/api/measurements/batch/route.ts
index df8ffcd59..1199e2354 100644
--- a/src/app/api/measurements/batch/route.ts
+++ b/src/app/api/measurements/batch/route.ts
@@ -620,6 +620,17 @@ async function postBatch(request: NextRequest): Promise<Response> {
           };
           failedCount++;
           continue;
+        case "rejected_range":
+          // The reconciler carries the same plausibility gate this route
+          // already applied above, so reaching here means the two disagreed —
+          // report it exactly as the earlier guard would have, and let the
+          // wide-event tally record which end refused.
+          results[p.index] = {
+            index: p.index,
+            status: "skipped",
+            reason: "value_out_of_range",
+          };
+          continue;
       }
 
       if (isMergeableSource(p.row.source as string)) {
diff --git a/src/components/labs/__tests__/lab-biomarker-detail.test.tsx b/src/components/labs/__tests__/lab-biomarker-detail.test.tsx
index bec4b97b6..a58b764ac 100644
--- a/src/components/labs/__tests__/lab-biomarker-detail.test.tsx
+++ b/src/components/labs/__tests__/lab-biomarker-detail.test.tsx
@@ -64,6 +64,13 @@ function reading(id: string, value: number, takenAt: string): LabResultDto {
     unit: "mg/dL",
     referenceLow: 0,
     referenceHigh: 100,
+    catalogReferenceLow: 0,
+    catalogReferenceHigh: 100,
+    sourceReferenceLow: null,
+    sourceReferenceHigh: null,
+    sourceReferenceText: null,
+    referenceOrigin: "catalog",
+    referenceDivergesFromCatalog: false,
     takenAt,
     source: "MANUAL",
     hasNote: false,
diff --git a/src/components/labs/lab-biomarker-chart.tsx b/src/components/labs/lab-biomarker-chart.tsx
index 96a48fad9..db6612d54 100644
--- a/src/components/labs/lab-biomarker-chart.tsx
+++ b/src/components/labs/lab-biomarker-chart.tsx
@@ -17,6 +17,7 @@ import { Button } from "@/components/ui/button";
 import { CHART_HEIGHT_PX } from "@/lib/charts/constants";
 import { prefersReducedMotion } from "@/lib/charts/reduced-motion";
 import { formatLabValue } from "@/lib/labs/format-value";
+import { formatReferenceRange } from "@/lib/labs/reference-range";
 import { useTranslations, useFormatters } from "@/lib/i18n/context";
 
 import { RichChartTooltip, type RichTooltipRow } from "../charts/chart-tooltip";
@@ -32,6 +33,15 @@ import type { LabResultDto } from "./types";
  * MUTED primary fill — never a danger colour — honouring the no-alarming-
  * colour rule. Every reading carries the same y-axis unit because a chart is
  * one biomarker only.
+ *
+ * A SECOND band draws the window a source report printed, when the readings in
+ * view carry one. It is visually distinct from the catalog band — an outlined
+ * band in the chart's secondary hue against the catalog's filled primary — and
+ * both stay muted; the in/out verdict is the badge's job, never the chart's
+ * colour. The source window is a per-reading fact, so the band is drawn from
+ * the NEWEST reading in view that carries one and the legend dates it. When
+ * the readings in view carry more than one distinct printed window the legend
+ * says so rather than implying one window covered the whole series.
  */
 
 const RANGE_DAYS = [
@@ -46,6 +56,26 @@ type RangeKey = (typeof RANGE_DAYS)[number]["key"];
 interface ChartPoint {
   timestamp: number;
   value: number;
+  /** The window this reading was judged against, for the tooltip. */
+  referenceLow: number | null;
+  referenceHigh: number | null;
+  referenceOrigin: LabResultDto["referenceOrigin"];
+  sourceReferenceText: string | null;
+}
+
+/** The source window drawn as the second band, resolved from the readings in view. */
+interface SourceBand {
+  low: number | null;
+  high: number | null;
+  /** The reading the band was taken from. */
+  takenAt: number;
+  /** True when the readings in view printed more than one distinct window. */
+  mixed: boolean;
+}
+
+/** Identity of a printed window, for counting distinct ones. */
+function bandKey(low: number | null, high: number | null): string {
+  return `${low ?? ""}|${high ?? ""}`;
 }
 
 export function LabBiomarkerChart({
@@ -87,9 +117,37 @@ export function LabBiomarkerChart({
     return filtered.map((r) => ({
       timestamp: new Date(r.takenAt).getTime(),
       value: r.value,
+      referenceLow: r.referenceLow,
+      referenceHigh: r.referenceHigh,
+      referenceOrigin: r.referenceOrigin,
+      sourceReferenceText: r.sourceReferenceText,
     }));
   }, [readings, range, nowMs]);
 
+  // The source band: the newest in-view reading whose report printed a window
+  // with usable bounds. Readings without one contribute nothing — an absent
+  // window is absent, not a reason to widen or narrow the band.
+  const sourceBand = useMemo<SourceBand | null>(() => {
+    const withWindow = points.filter(
+      (p) =>
+        p.referenceOrigin === "source" &&
+        (p.referenceLow !== null || p.referenceHigh !== null),
+    );
+    if (withWindow.length === 0) return null;
+    const newest = withWindow.reduce((a, b) =>
+      b.timestamp > a.timestamp ? b : a,
+    );
+    const distinct = new Set(
+      withWindow.map((p) => bandKey(p.referenceLow, p.referenceHigh)),
+    );
+    return {
+      low: newest.referenceLow,
+      high: newest.referenceHigh,
+      takenAt: newest.timestamp,
+      mixed: distinct.size > 1,
+    };
+  }, [points]);
+
   // Y domain wraps both the data and the reference window so the band is
   // always visible even when every reading sits inside it.
   const yDomain = useMemo<[number, number]>(() => {
@@ -97,15 +155,23 @@ export function LabBiomarkerChart({
     const candidates = [...values];
     if (lowerBound != null) candidates.push(lowerBound);
     if (upperBound != null) candidates.push(upperBound);
+    // The source band has to fit too, or the second band is drawn off-canvas
+    // and the chart silently shows one window while claiming two.
+    if (sourceBand?.low != null) candidates.push(sourceBand.low);
+    if (sourceBand?.high != null) candidates.push(sourceBand.high);
     if (candidates.length === 0) return [0, 1];
     const min = Math.min(...candidates);
     const max = Math.max(...candidates);
     const pad = (max - min || Math.abs(max) || 1) * 0.1;
     return [min - pad, max + pad];
-  }, [points, lowerBound, upperBound]);
+  }, [points, lowerBound, upperBound, sourceBand]);
 
   const animate = !prefersReducedMotion();
   const primary = "var(--primary)";
+  // A second muted hue from the chart palette. Distinct from the primary band
+  // by hue AND by treatment (outline vs fill), so the two are told apart
+  // without relying on colour alone.
+  const secondary = "var(--chart-2)";
 
   return (
     <div className="space-y-3">
@@ -185,6 +251,42 @@ export function LabBiomarkerChart({
                   strokeDasharray="4 4"
                 />
               ) : null}
+              {/* The source window — outlined, not filled, so it reads as a
+                  second band over the catalog one rather than a second fill
+                  competing with it. Same no-alarm-colour rule. */}
+              {sourceBand &&
+              sourceBand.low != null &&
+              sourceBand.high != null ? (
+                <ReferenceArea
+                  y1={sourceBand.low}
+                  y2={sourceBand.high}
+                  fill={secondary}
+                  fillOpacity={0.06}
+                  stroke={secondary}
+                  strokeOpacity={0.5}
+                  strokeDasharray="2 3"
+                />
+              ) : null}
+              {sourceBand &&
+              sourceBand.low != null &&
+              sourceBand.high == null ? (
+                <ReferenceLine
+                  y={sourceBand.low}
+                  stroke={secondary}
+                  strokeOpacity={0.6}
+                  strokeDasharray="2 3"
+                />
+              ) : null}
+              {sourceBand &&
+              sourceBand.high != null &&
+              sourceBand.low == null ? (
+                <ReferenceLine
+                  y={sourceBand.high}
+                  stroke={secondary}
+                  strokeOpacity={0.6}
+                  strokeDasharray="2 3"
+                />
+              ) : null}
               <Tooltip
                 content={(props) => {
                   const active = props.active ?? false;
@@ -201,6 +303,22 @@ export function LabBiomarkerChart({
                       color: primary,
                     },
                   ];
+                  // Name the window THIS reading was judged against. Two
+                  // readings on one chart can carry different printed windows,
+                  // so the band alone cannot answer it per point.
+                  if (point.referenceOrigin === "source") {
+                    rows.push({
+                      name: t("labs.chart.sourceRangeLabel"),
+                      value:
+                        point.sourceReferenceText ??
+                        `${formatReferenceRange(
+                          point.referenceLow,
+                          point.referenceHigh,
+                          formatLabValue,
+                        )} ${unit}`.trim(),
+                      color: secondary,
+                    });
+                  }
                   return (
                     <RichChartTooltip
                       active
@@ -221,6 +339,15 @@ export function LabBiomarkerChart({
               />
             </ComposedChart>
           </ResponsiveContainer>
+          {sourceBand ? (
+            <p className="text-muted-foreground mt-2 text-xs">
+              {sourceBand.mixed
+                ? t("labs.chart.sourceBandMixed")
+                : t("labs.chart.sourceBandLegend", {
+                    date: fmt.dateShortSmart(new Date(sourceBand.takenAt)),
+                  })}
+            </p>
+          ) : null}
         </div>
       )}
     </div>
diff --git a/src/components/labs/lab-form.tsx b/src/components/labs/lab-form.tsx
index 476c5da8a..4e865e9dd 100644
--- a/src/components/labs/lab-form.tsx
+++ b/src/components/labs/lab-form.tsx
@@ -22,6 +22,7 @@ import {
 import { Textarea } from "@/components/ui/textarea";
 import { apiGet, apiPost } from "@/lib/api/api-fetch";
 import { localizedApiError } from "@/lib/api/localized-error";
+import { parseReferenceRange } from "@/lib/labs/parse-reference-range";
 import { formatReferenceRange } from "@/lib/labs/reference-range";
 import { formatLabValue } from "@/lib/labs/format-value";
 import { useTranslations } from "@/lib/i18n/context";
@@ -118,6 +119,13 @@ export function LabForm({
   const [valueText, setValueText] = useState("");
   const [takenAt, setTakenAt] = useState(defaultTakenAtValue);
   const [note, setNote] = useState("");
+  // The window the paper report printed for THIS reading. Optional and folded
+  // away by default: most entries are typed against a catalog marker and never
+  // need it, and a field nobody fills is a field in the way. One text input,
+  // because that is how a report states it — "3,5 - 5,0", "< 5", "bis 5,0".
+  // The bounds are derived from what is typed; what is typed is kept verbatim.
+  const [sourceRangeOpen, setSourceRangeOpen] = useState(false);
+  const [sourceRange, setSourceRange] = useState("");
   // v1.30.1 H3 — which submit button is in flight, so the OTHER one doesn't
   // also show a spinner. `!== null` replaces the old plain `submitting`
   // boolean for every disabled check below.
@@ -193,11 +201,27 @@ export function LabForm({
 
     setPendingAction(keepOpen ? "saveAndAddAnother" : "save");
     try {
+      // Parse client-side so the user sees the derived window before saving,
+      // and send BOTH: the bounds where they could be read, the text always.
+      const printed = isQualitative
+        ? null
+        : parseReferenceRange(sourceRange, selected?.unit);
       const created = await apiPost<LabResultDto>("/api/labs", {
         biomarkerId,
         ...(isQualitative
           ? { valueText: qualitativeValue }
           : { value: numericValue }),
+        ...(printed
+          ? {
+              ...(printed.low !== null
+                ? { sourceReferenceLow: printed.low }
+                : {}),
+              ...(printed.high !== null
+                ? { sourceReferenceHigh: printed.high }
+                : {}),
+              sourceReferenceText: printed.text,
+            }
+          : {}),
         takenAt: new Date(takenAt).toISOString(),
         ...(note.trim() ? { note: note.trim() } : {}),
       });
@@ -221,6 +245,8 @@ export function LabForm({
         setValue("");
         setValueText("");
         setNote("");
+        // The next analyte off the same report has its own printed window.
+        setSourceRange("");
         setError(null);
         onSavedKeepOpen?.(created);
         // Return focus to wherever the next entry starts so the flow
@@ -252,6 +278,20 @@ export function LabForm({
       )
     : "";
 
+  // What the typed string resolved to, shown back so the user can see whether
+  // a window was read out of it before the reading is saved. When none was,
+  // the hint says the text is kept as written rather than staying silent.
+  const parsedSourceRange = parseReferenceRange(sourceRange, selected?.unit);
+  const sourceRangeHint = parsedSourceRange
+    ? parsedSourceRange.low === null && parsedSourceRange.high === null
+      ? t("labs.form.sourceRangeUnparsed")
+      : `${formatReferenceRange(
+          parsedSourceRange.low,
+          parsedSourceRange.high,
+          formatLabValue,
+        )} ${selected?.unit ?? ""}`.trim()
+    : "";
+
   const footerNode = (
     <>
       {onCancel ? (
@@ -415,6 +455,39 @@ export function LabForm({
           </p>
         ) : null}
 
+        {resultType === "numeric" ? (
+          <div className="space-y-1.5">
+            {sourceRangeOpen ? (
+              <>
+                <Label htmlFor="lab-sourceRange">
+                  {t("labs.form.sourceRange")}
+                </Label>
+                <Input
+                  id="lab-sourceRange"
+                  value={sourceRange}
+                  onChange={(e) => setSourceRange(e.target.value)}
+                  placeholder={t("labs.form.sourceRangePlaceholder")}
+                  maxLength={120}
+                  autoFocus
+                />
+                <p className="text-muted-foreground text-xs">
+                  {sourceRangeHint || t("labs.form.sourceRangeHint")}
+                </p>
+              </>
+            ) : (
+              <Button
+                type="button"
+                variant="ghost"
+                size="sm"
+                className="text-muted-foreground h-auto px-0 text-xs"
+                onClick={() => setSourceRangeOpen(true)}
+              >
+                {t("labs.form.sourceRangeAdd")}
+              </Button>
+            )}
+          </div>
+        ) : null}
+
         <div className="space-y-1.5">
           <Label htmlFor="lab-note">{t("labs.form.note")}</Label>
           <Textarea
diff --git a/src/components/labs/lab-history-list.tsx b/src/components/labs/lab-history-list.tsx
index 329ce1561..16f7052ba 100644
--- a/src/components/labs/lab-history-list.tsx
+++ b/src/components/labs/lab-history-list.tsx
@@ -35,6 +35,7 @@ import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
 
 import { ReferenceRangeBadge } from "./reference-range-badge";
+import { SourceRangeNote } from "./source-range-note";
 import type { LabResultDetailDto, LabResultDto } from "./types";
 
 const NOTE_MAX_LENGTH = 2000;
@@ -356,7 +357,13 @@ export function LabHistoryList({ readings }: { readings: LabResultDto[] }) {
                 {formatDateShort(r.takenAt, true)}
               </TableCell>
               <TableCell>
-                <ReferenceRangeBadge status={r.rangeStatus} />
+                <div className="flex flex-col items-start gap-1">
+                  <ReferenceRangeBadge status={r.rangeStatus} />
+                  <SourceRangeNote
+                    reading={r}
+                    className="text-muted-foreground text-xs"
+                  />
+                </div>
               </TableCell>
               <TableCell className="text-muted-foreground text-sm">
                 {r.hasNote ? t("labs.hasNote") : ""}
diff --git a/src/components/labs/lab-list.tsx b/src/components/labs/lab-list.tsx
index 99573ec0b..c3207f4e9 100644
--- a/src/components/labs/lab-list.tsx
+++ b/src/components/labs/lab-list.tsx
@@ -23,6 +23,7 @@ import { applyOrder, useModuleListPrefs } from "@/lib/module-list-prefs";
 
 import { LabTrendSparkline } from "./lab-trend-sparkline";
 import { ReferenceRangeBadge } from "./reference-range-badge";
+import { SourceRangeNote } from "./source-range-note";
 import type { LabResultDto, LabResultListResponse } from "./types";
 
 interface MarkerGroup {
@@ -316,6 +317,10 @@ export function LabList({ onAddFirst }: { onAddFirst?: () => void } = {}) {
                         )}
                       </span>
                     ) : null}
+                    <SourceRangeNote
+                      reading={group.latest}
+                      className="text-xs"
+                    />
                     <span className="text-xs">
                       {formatDate(group.latest.takenAt)}
                     </span>
diff --git a/src/components/labs/ocr-review-dialog.tsx b/src/components/labs/ocr-review-dialog.tsx
index 64a84bf44..29eee6ce6 100644
--- a/src/components/labs/ocr-review-dialog.tsx
+++ b/src/components/labs/ocr-review-dialog.tsx
@@ -76,6 +76,7 @@ function toCommitRow(row: OcrReviewRow): OcrCommitRowInput | null {
     takenAt: takenAt.toISOString(),
     ...(row.referenceLow !== null ? { referenceLow: row.referenceLow } : {}),
     ...(row.referenceHigh !== null ? { referenceHigh: row.referenceHigh } : {}),
+    ...(row.referenceText ? { referenceText: row.referenceText } : {}),
   };
 }
 
diff --git a/src/components/labs/ocr-review-types.ts b/src/components/labs/ocr-review-types.ts
index 1384cb0fd..825aa77ad 100644
--- a/src/components/labs/ocr-review-types.ts
+++ b/src/components/labs/ocr-review-types.ts
@@ -16,6 +16,8 @@ export interface OcrReviewRow {
   unit: string | null;
   referenceLow: number | null;
   referenceHigh: number | null;
+  /** The reference range as printed on the scanned report, verbatim. */
+  referenceText: string | null;
   /** ISO calendar day (YYYY-MM-DD) or null. */
   takenAt: string | null;
   confidence: OcrExtractedRowDto["confidence"];
@@ -39,6 +41,7 @@ export function seedReviewRows(
     unit: row.unit,
     referenceLow: row.referenceLow,
     referenceHigh: row.referenceHigh,
+    referenceText: row.referenceText,
     takenAt: row.takenAt ?? fallbackDate,
     confidence: row.confidence,
     biomarkerMatch: row.biomarkerMatch,
diff --git a/src/components/labs/ocr-row-editor.tsx b/src/components/labs/ocr-row-editor.tsx
index f3838308d..f11aa5bb2 100644
--- a/src/components/labs/ocr-row-editor.tsx
+++ b/src/components/labs/ocr-row-editor.tsx
@@ -247,6 +247,32 @@ export function OcrRowEditor({
         </div>
       ) : null}
 
+      {/* The window as the report printed it. Editable, because the human is
+          reviewing a transcription: the two bounds above are the derived
+          reading of this string, and correcting the string is how a range the
+          parser could not read ("bis 5,0", "negativ") still reaches the row
+          instead of being dropped. */}
+      {!isQualitative ? (
+        <div className="space-y-1">
+          <Label htmlFor={`${fieldId}-refText`} className="text-xs">
+            {t("labs.ocr.refTextLabel")}
+          </Label>
+          <Input
+            id={`${fieldId}-refText`}
+            value={row.referenceText ?? ""}
+            placeholder={t("labs.ocr.refTextPlaceholder")}
+            maxLength={120}
+            onChange={(e) => {
+              const raw = e.target.value;
+              onChange({
+                ...row,
+                referenceText: raw.trim() === "" ? null : raw,
+              });
+            }}
+          />
+        </div>
+      ) : null}
+
       {valueUnreadable ? (
         <p className="text-muted-foreground flex items-center gap-1.5 text-xs">
           <AlertCircle aria-hidden className="h-3.5 w-3.5" />
diff --git a/src/components/labs/source-range-note.tsx b/src/components/labs/source-range-note.tsx
new file mode 100644
index 000000000..2fb6e6929
--- /dev/null
+++ b/src/components/labs/source-range-note.tsx
@@ -0,0 +1,69 @@
+"use client";
+
+import { formatLabValue } from "@/lib/labs/format-value";
+import { formatReferenceRange } from "@/lib/labs/reference-range";
+import { useTranslations } from "@/lib/i18n/context";
+
+import type { LabResultDto } from "./types";
+
+/**
+ * The reference window a reading's own report printed, shown wherever that
+ * reading is shown.
+ *
+ * Renders nothing for a reading with no printed window — most of them — so it
+ * costs no space on the common row. When the report DID state a window it
+ * names it, verbatim where the report gave words; and when that window and the
+ * catalog band disagree it names the catalog band too. A reader told only
+ * "3,9–5,4" and a reader told only "3,5–5,0" draw different conclusions from
+ * the same number, so a surface that shows one silently is showing a partial
+ * answer.
+ *
+ * Neutral by construction: no tint, no icon, muted text. The in/out verdict is
+ * the badge's job — this element states where the window came from, nothing
+ * about whether the value is good news.
+ */
+export function SourceRangeNote({
+  reading,
+  className,
+}: {
+  reading: Pick<
+    LabResultDto,
+    | "unit"
+    | "referenceLow"
+    | "referenceHigh"
+    | "catalogReferenceLow"
+    | "catalogReferenceHigh"
+    | "sourceReferenceText"
+    | "referenceOrigin"
+    | "referenceDivergesFromCatalog"
+  >;
+  className?: string;
+}) {
+  const { t } = useTranslations();
+  if (reading.referenceOrigin !== "source") return null;
+
+  const printed =
+    reading.sourceReferenceText ??
+    `${formatReferenceRange(
+      reading.referenceLow,
+      reading.referenceHigh,
+      formatLabValue,
+    )} ${reading.unit}`.trim();
+
+  const catalog = formatReferenceRange(
+    reading.catalogReferenceLow,
+    reading.catalogReferenceHigh,
+    formatLabValue,
+  );
+
+  return (
+    <span className={className}>
+      {t("labs.sourceRange.fromReport", { range: printed })}
+      {reading.referenceDivergesFromCatalog && catalog
+        ? ` · ${t("labs.sourceRange.catalogDiffers", {
+            range: `${catalog} ${reading.unit}`.trim(),
+          })}`
+        : null}
+    </span>
+  );
+}
diff --git a/src/components/labs/types.ts b/src/components/labs/types.ts
index a3448eb69..2f7eae4a4 100644
--- a/src/components/labs/types.ts
+++ b/src/components/labs/types.ts
@@ -1,4 +1,7 @@
-import type { ReferenceRangeStatus } from "@/lib/validations/labs";
+import type {
+  ReferenceRangeOrigin,
+  ReferenceRangeStatus,
+} from "@/lib/validations/labs";
 
 /** A lab-result row as the list / create endpoints serialise it. */
 export interface LabResultDto {
@@ -12,8 +15,25 @@ export interface LabResultDto {
   /** v1.18.9 — qualitative result text ("negativ" / …); null for a numeric row. */
   valueText: string | null;
   unit: string;
+  /**
+   * The window this reading is judged against and the one `rangeStatus` was
+   * computed from: the range its own report printed when it carries one, the
+   * catalog band otherwise. Render these and the range shown always matches
+   * the verdict shown.
+   */
   referenceLow: number | null;
   referenceHigh: number | null;
+  /** The catalog marker's band, so both windows can be drawn. */
+  catalogReferenceLow: number | null;
+  catalogReferenceHigh: number | null;
+  /** The window the source report printed; the text verbatim, bounds when derivable. */
+  sourceReferenceLow: number | null;
+  sourceReferenceHigh: number | null;
+  sourceReferenceText: string | null;
+  /** Which window is in force. */
+  referenceOrigin: ReferenceRangeOrigin;
+  /** True when the report's window and the catalog band state different limits. */
+  referenceDivergesFromCatalog: boolean;
   takenAt: string;
   source: string;
   hasNote: boolean;
diff --git a/src/components/labs/use-ocr-extract.ts b/src/components/labs/use-ocr-extract.ts
index 7f2bd30c7..ee05cfdb2 100644
--- a/src/components/labs/use-ocr-extract.ts
+++ b/src/components/labs/use-ocr-extract.ts
@@ -33,6 +33,7 @@ export interface OcrCommitRowInput {
   unit?: string;
   referenceLow?: number;
   referenceHigh?: number;
+  referenceText?: string;
   takenAt: string;
 }
 
diff --git a/src/lib/ai/coach/labs-snapshot.ts b/src/lib/ai/coach/labs-snapshot.ts
index e5c791ded..50c3ee109 100644
--- a/src/lib/ai/coach/labs-snapshot.ts
+++ b/src/lib/ai/coach/labs-snapshot.ts
@@ -37,7 +37,7 @@
  * is always owner-scoped and safe to read), so the block is `null` only when the
  * account has no recent readings.
  */
-import { classifyReferenceRange } from "@/lib/labs/reference-range";
+import { classifyAgainstEffectiveRange } from "@/lib/labs/reference-range";
 import { resolveLabFields } from "@/lib/labs/serialise";
 import { sanitizeForPrompt } from "@/lib/insights/sanitize";
 import { prisma } from "@/lib/db";
@@ -131,6 +131,9 @@ export async function buildLabsSnapshotBlock(
       unit: true,
       referenceLow: true,
       referenceHigh: true,
+      sourceReferenceLow: true,
+      sourceReferenceHigh: true,
+      sourceReferenceText: true,
       takenAt: true,
       biomarkerId: true,
       biomarker: {
@@ -181,15 +184,13 @@ export async function buildLabsSnapshotBlock(
       referenceLow: resolved.referenceLow,
       referenceHigh: resolved.referenceHigh,
       // A qualitative row has nothing to compare against the bounds → neutral
-      // "unknown", never a fabricated verdict. A numeric row classifies.
-      rangeStatus:
-        row.value === null
-          ? "unknown"
-          : classifyReferenceRange(
-              row.value,
-              resolved.referenceLow,
-              resolved.referenceHigh,
-            ),
+      // "unknown", never a fabricated verdict. A numeric row classifies against
+      // the window in force for it — the report's own range when it carries
+      // one, the catalog band otherwise. Same rule as every other lab surface.
+      rangeStatus: classifyAgainstEffectiveRange(
+        row.value,
+        resolved.effectiveRange,
+      ),
       takenAt: row.takenAt.toISOString(),
     });
 
diff --git a/src/lib/doctor-report-pdf/clinical-records-notes-section.ts b/src/lib/doctor-report-pdf/clinical-records-notes-section.ts
index 7aadda451..464f1f85f 100644
--- a/src/lib/doctor-report-pdf/clinical-records-notes-section.ts
+++ b/src/lib/doctor-report-pdf/clinical-records-notes-section.ts
@@ -20,10 +20,18 @@ export function buildClinicalRecordsNotesSection(
 
   // v1.17.1 — structured lab-results section. Populated when the `labs`
   // toggle is ON (default) and the user recorded at least one result in the
-  // window. One row per analyte (latest reading), with the lab's reference
-  // range and a NEUTRAL in/out-of-range marker — informative, never an
-  // alarming red. The marker is a quiet glyph (↓ / ↑ / —), not a colour, so
-  // the clinical PDF stays calm.
+  // window. One row per analyte (latest reading), with the reference range and
+  // a NEUTRAL in/out-of-range marker — informative, never an alarming red. The
+  // marker is a quiet glyph (↓ / ↑ / —), not a colour, so the clinical PDF
+  // stays calm.
+  //
+  // The reference column prints the window the reading was JUDGED against, and
+  // when that window came off the source report it prints the report's own
+  // string verbatim — a clinician comparing this table against the original
+  // report should read the same characters. A reading whose report window
+  // differs from the catalog band carries a footnote marker, and the catalog
+  // band is named beneath the table, because "3,9–5,4" and "3,5–5,0" disagree
+  // about the same number and a table that shows only one is a partial answer.
   if (data.labResults && data.labResults.length > 0) {
     y = ensureSpace(y, 6 + 18);
     doc.setFontSize(14);
@@ -54,6 +62,23 @@ export function buildClinicalRecordsNotesSection(
       }
     };
 
+    // The reference cell: the report's own string when the report stated the
+    // window, else the formatted catalog band. A divergence gets a "*" the
+    // note under the table explains.
+    const referenceCell = (
+      lr: NonNullable<typeof data.labResults>[number],
+    ): string => {
+      const printed =
+        lr.referenceOrigin === "source" && lr.sourceReferenceText
+          ? lr.sourceReferenceText
+          : rangeText(lr.referenceLow, lr.referenceHigh);
+      return lr.referenceDivergesFromCatalog ? `${printed} *` : printed;
+    };
+
+    const diverging = data.labResults.filter(
+      (lr) => lr.referenceDivergesFromCatalog,
+    );
+
     const labRows = data.labResults.map((lr) => {
       // v1.18.9 — a qualitative reading (`value === null`) prints its result
       // text in the value column and has no numeric range / status glyph.
@@ -63,7 +88,7 @@ export function buildClinicalRecordsNotesSection(
         isQualitative
           ? (lr.valueText ?? "")
           : `${num(lr.value as number)} ${lr.unit}`.trim(),
-        isQualitative ? "—" : rangeText(lr.referenceLow, lr.referenceHigh),
+        isQualitative ? "—" : referenceCell(lr),
         isQualitative
           ? ""
           : statusGlyph(lr.value as number, lr.referenceLow, lr.referenceHigh),
@@ -107,6 +132,30 @@ export function buildClinicalRecordsNotesSection(
     y =
       (doc as jsPDF & { lastAutoTable: { finalY: number } }).lastAutoTable
         .finalY + 8;
+
+    // Name every diverging marker's catalog band, so the reader can see both
+    // windows rather than being told only that they differ.
+    if (diverging.length > 0) {
+      y = ensureSpace(y, 4 + diverging.length * 4);
+      doc.setFontSize(8);
+      doc.setFont("helvetica", "normal");
+      doc.setTextColor(110, 110, 110);
+      doc.text(t("doctorReport.labsSourceRangeNote"), margin, y);
+      y += 4;
+      for (const lr of diverging) {
+        doc.text(
+          `* ${lr.analyte}: ${t("doctorReport.labsCatalogRangeLabel")} ${rangeText(
+            lr.catalogReferenceLow,
+            lr.catalogReferenceHigh,
+          )} ${lr.unit}`.trim(),
+          margin,
+          y,
+        );
+        y += 4;
+      }
+      doc.setTextColor(30, 30, 30);
+      y += 4;
+    }
   }
 
   // v1.18.1 P4 — illness / condition episodes overlapping the window. Present
diff --git a/src/lib/doctor-report-types.ts b/src/lib/doctor-report-types.ts
index 05c6cf41e..1d1de1c0d 100644
--- a/src/lib/doctor-report-types.ts
+++ b/src/lib/doctor-report-types.ts
@@ -241,8 +241,23 @@ export interface DoctorReportData {
      */
     valueText: string | null;
     unit: string;
+    /**
+     * The reference window this reading is judged against: the range printed
+     * on its own report when it carries one, the catalog band otherwise.
+     * Resolved server-side through `resolveEffectiveReferenceRange` so the PDF
+     * marker, the FHIR `referenceRange`, and the API verdict agree.
+     */
     referenceLow: number | null;
     referenceHigh: number | null;
+    /** The catalog band, kept so the PDF can name a divergence. */
+    catalogReferenceLow: number | null;
+    catalogReferenceHigh: number | null;
+    /** The window the source report printed, verbatim; null when it printed none. */
+    sourceReferenceText: string | null;
+    /** Which of the two windows `referenceLow` / `referenceHigh` came from. */
+    referenceOrigin: "source" | "catalog" | "none";
+    /** True when the report's window and the catalog band state different limits. */
+    referenceDivergesFromCatalog: boolean;
     /** ISO timestamp of the latest reading. */
     takenAt: string;
     /** Count of readings for this analyte in the window (≥ 1). */
diff --git a/src/lib/doctor-report/clinical-records.ts b/src/lib/doctor-report/clinical-records.ts
index aec85ac8d..9553a15db 100644
--- a/src/lib/doctor-report/clinical-records.ts
+++ b/src/lib/doctor-report/clinical-records.ts
@@ -11,6 +11,7 @@
  * Split out of the aggregator with the selection rework.
  */
 import { prisma } from "@/lib/db";
+import { resolveEffectiveReferenceRange } from "@/lib/labs/reference-range";
 import { getEvent } from "@/lib/logging/context";
 import { decryptAllergyReaction } from "@/lib/doctor-report-helpers";
 import type { DoctorReportData } from "@/lib/doctor-report-types";
@@ -42,6 +43,9 @@ export async function loadLabResults(
       unit: true,
       referenceLow: true,
       referenceHigh: true,
+      sourceReferenceLow: true,
+      sourceReferenceHigh: true,
+      sourceReferenceText: true,
       takenAt: true,
     },
   });
@@ -52,14 +56,28 @@ export async function loadLabResults(
   for (const r of rows) {
     const key = r.analyte.toLowerCase();
     const prev = byAnalyte.get(key);
+    // The row already stamps the catalog band it was written under; the
+    // reading's own report window, when present, is what the physician read
+    // the value against, so it wins here exactly as it does on every other
+    // lab surface.
+    const range = resolveEffectiveReferenceRange(
+      r.referenceLow,
+      r.referenceHigh,
+      r,
+    );
     byAnalyte.set(key, {
       panel: r.panel,
       analyte: r.analyte,
       value: r.value,
       valueText: r.valueText,
       unit: r.unit,
-      referenceLow: r.referenceLow,
-      referenceHigh: r.referenceHigh,
+      referenceLow: range.low,
+      referenceHigh: range.high,
+      catalogReferenceLow: range.catalogLow,
+      catalogReferenceHigh: range.catalogHigh,
+      sourceReferenceText: range.sourceText,
+      referenceOrigin: range.origin,
+      referenceDivergesFromCatalog: range.divergesFromCatalog,
       takenAt: r.takenAt.toISOString(),
       count: (prev?.count ?? 0) + 1,
     });
diff --git a/src/lib/documents/commit.ts b/src/lib/documents/commit.ts
index ab5e1f6db..b960b39b9 100644
--- a/src/lib/documents/commit.ts
+++ b/src/lib/documents/commit.ts
@@ -15,6 +15,12 @@
  * as-needed medication with notifications off — a record of what the patient
  * takes, never a prescription action. An Observation never carries a
  * range-flag; the reference bounds ride along only as the document stated them.
+ *
+ * The window the report printed beside a value is carried onto the reading, not
+ * dropped. Until now it only seeded a freshly minted catalog marker, which meant
+ * that for every analyte the user already had, the range printed on the report
+ * was read and then thrown away. It now lands on the row's `sourceReference*`
+ * columns and governs that reading's verdict.
  */
 import { encryptToBytes } from "@/lib/ai/coach/bytes-codec";
 import { prisma } from "@/lib/db";
@@ -22,6 +28,7 @@ import { invalidateUserHealthScore } from "@/lib/cache/invalidate";
 import { emitDataArrival } from "@/lib/arrivals/emit-shared";
 import { decryptFactData } from "@/lib/documents/store";
 import { resolveOrMintBiomarker } from "@/lib/labs/biomarker-store";
+import { parseReferenceRange } from "@/lib/labs/parse-reference-range";
 import type { ExtractedFact } from "@/generated/prisma/client";
 import type {
   ConditionFactData,
@@ -66,11 +73,21 @@ async function commitObservation(
       "A numeric value needs a unit before it can be saved",
     );
   }
+  // The printed window, read once. `referenceText` is what the report wrote;
+  // the parser derives bounds from it where it can, and where it cannot the
+  // string still survives onto the row. A document staged before the field
+  // existed has no text, and the numeric bounds the model reported are then
+  // the whole of what it stated.
+  const printed = parseReferenceRange(data.referenceText, data.unit);
+  const sourceLow = printed?.low ?? data.referenceLow;
+  const sourceHigh = printed?.high ?? data.referenceHigh;
+  const sourceText = printed?.text ?? null;
+
   const biomarker = await resolveOrMintBiomarker(userId, {
     analyte: data.label,
     unit: isQualitative ? (data.unit ?? "") : (data.unit as string),
-    referenceLow: isQualitative ? null : data.referenceLow,
-    referenceHigh: isQualitative ? null : data.referenceHigh,
+    referenceLow: isQualitative ? null : sourceLow,
+    referenceHigh: isQualitative ? null : sourceHigh,
     panel: null,
   });
   // Fail closed on a unit mismatch against an EXISTING marker. A freshly
@@ -101,6 +118,11 @@ async function commitObservation(
       unit: biomarker.unit,
       referenceLow: biomarker.lowerBound,
       referenceHigh: biomarker.upperBound,
+      // The report's own window for THIS reading. A qualitative result has no
+      // window to record.
+      sourceReferenceLow: isQualitative ? null : sourceLow,
+      sourceReferenceHigh: isQualitative ? null : sourceHigh,
+      sourceReferenceText: isQualitative ? null : sourceText,
       takenAt: statedDateOrNow(data.effectiveDate),
       source: "DOCUMENT",
       noteEncrypted: null,
diff --git a/src/lib/documents/extract.ts b/src/lib/documents/extract.ts
index e33508cdb..3d02c342c 100644
--- a/src/lib/documents/extract.ts
+++ b/src/lib/documents/extract.ts
@@ -74,7 +74,8 @@ Extract these fact types:
    - code + codeSystem ("LOINC"): ONLY if a code is printed, else null.
    - value: the numeric result OR null. valueText: the qualitative result text (e.g. "negative") OR null. Set EXACTLY ONE.
    - unit: the printed unit, or null. NEVER convert or normalise a unit.
-   - referenceLow / referenceHigh: the printed reference bounds as numbers, or null. Do NOT flag the value against them.
+   - referenceText: the reference range EXACTLY as printed beside the value, verbatim and complete, including its operator and unit if written (for example "3,5 - 5,0", "< 5", "bis 5,0", "\u2265 3,5", "150.000 - 400.000 /\u00b5l", "negativ"). Copy the characters; do NOT reformat, convert, or normalise them. Null only when no range is printed for that value.
+   - referenceLow / referenceHigh: the SAME range reduced to two numbers, when it reduces to two numbers, else null. Do NOT flag the value against them.
    - effectiveDate: the stated measurement date (YYYY-MM-DD), else null.
 3. MEDICATION_STATEMENT — a medication the patient is/was taking, as recorded. Capture:
    - label: the drug name, verbatim.
@@ -91,7 +92,7 @@ For EVERY fact also capture:
 Do not emit a fact you cannot read — omit it rather than invent one. Also capture reportDate: the document's stated report/collection date (YYYY-MM-DD), or null, and kind: "DOCTOR_REPORT", "DISCHARGE_LETTER", or "OTHER".
 
 Respond ONLY with a JSON object of this exact shape:
-{ "reportDate": string|null, "kind": "DOCTOR_REPORT"|"DISCHARGE_LETTER"|"OTHER"|null, "facts": [ { "type": "CONDITION"|"OBSERVATION"|"MEDICATION_STATEMENT", "label": string, "code": string|null, "codeSystem": "SNOMED"|"ICD10"|"LOINC"|"RXNORM"|"ATC"|null, "clinicalStatus": string|null, "verificationStatus": string|null, "value": number|null, "valueText": string|null, "unit": string|null, "referenceLow": number|null, "referenceHigh": number|null, "dose": string|null, "medicationStatus": string|null, "effectiveDate": string|null, "sourceText": string, "page": number|null, "confidence": number } ] }`;
+{ "reportDate": string|null, "kind": "DOCTOR_REPORT"|"DISCHARGE_LETTER"|"OTHER"|null, "facts": [ { "type": "CONDITION"|"OBSERVATION"|"MEDICATION_STATEMENT", "label": string, "code": string|null, "codeSystem": "SNOMED"|"ICD10"|"LOINC"|"RXNORM"|"ATC"|null, "clinicalStatus": string|null, "verificationStatus": string|null, "value": number|null, "valueText": string|null, "unit": string|null, "referenceText": string|null, "referenceLow": number|null, "referenceHigh": number|null, "dose": string|null, "medicationStatus": string|null, "effectiveDate": string|null, "sourceText": string, "page": number|null, "confidence": number } ] }`;
 
 const USER_PROMPT = `Transcribe the clinical document in the attached file into the JSON schema described in the system prompt. Reproduce only what is written — do not interpret. Return only the JSON object.`;
 
@@ -172,6 +173,7 @@ function mapFactData(raw: ExtractedFactRaw): FactData | null {
       unit: raw.unit,
       referenceLow: raw.referenceLow,
       referenceHigh: raw.referenceHigh,
+      referenceText: raw.referenceText,
       effectiveDate,
     };
     return data;
@@ -309,6 +311,14 @@ export async function runInboundExtraction(
       unanchored,
       conditions: facts.filter((f) => f.factType === "CONDITION").length,
       observations: facts.filter((f) => f.factType === "OBSERVATION").length,
+      // How many transcribed observations arrived with the window the report
+      // printed beside them. A collapse here is the extraction quietly going
+      // back to dropping the range.
+      observationsWithRange: facts.filter(
+        (f) =>
+          f.factType === "OBSERVATION" &&
+          ((f.data as ObservationFactData).referenceText ?? null) !== null,
+      ).length,
       medications: facts.filter((f) => f.factType === "MEDICATION_STATEMENT")
         .length,
       needsReview: facts.filter((f) => f.needsReview).length,
diff --git a/src/lib/export/records-backup.ts b/src/lib/export/records-backup.ts
index c41ea32bb..34db3c428 100644
--- a/src/lib/export/records-backup.ts
+++ b/src/lib/export/records-backup.ts
@@ -54,6 +54,10 @@ export interface LabResultBackupEntry {
   unit: string;
   referenceLow: number | null;
   referenceHigh: number | null;
+  /** The window the reading's own source report printed, verbatim + derived. */
+  sourceReferenceLow: number | null;
+  sourceReferenceHigh: number | null;
+  sourceReferenceText: string | null;
   takenAt: string;
   source: string;
   /** Human-readable cross-reference into `biomarkers` below, not an id. */
@@ -336,6 +340,9 @@ export async function buildRecordsBackupSection(
     unit: r.unit,
     referenceLow: r.referenceLow,
     referenceHigh: r.referenceHigh,
+    sourceReferenceLow: r.sourceReferenceLow,
+    sourceReferenceHigh: r.sourceReferenceHigh,
+    sourceReferenceText: r.sourceReferenceText,
     takenAt: r.takenAt.toISOString(),
     source: r.source,
     biomarkerName: r.biomarker?.name ?? null,
diff --git a/src/lib/fhir/__tests__/lab-observations.test.ts b/src/lib/fhir/__tests__/lab-observations.test.ts
index d2f647f5a..9c2c4080b 100644
--- a/src/lib/fhir/__tests__/lab-observations.test.ts
+++ b/src/lib/fhir/__tests__/lab-observations.test.ts
@@ -54,6 +54,11 @@ describe("lab-result FHIR Observations", () => {
       unit: "mg/dL",
       referenceLow: null,
       referenceHigh: 116,
+      catalogReferenceLow: null,
+      catalogReferenceHigh: null,
+      sourceReferenceText: null,
+      referenceOrigin: "catalog" as const,
+      referenceDivergesFromCatalog: false,
       takenAt: "2026-04-20T08:00:00.000Z",
       count: 2,
     },
@@ -65,6 +70,11 @@ describe("lab-result FHIR Observations", () => {
       unit: "%",
       referenceLow: 4,
       referenceHigh: 5.6,
+      catalogReferenceLow: null,
+      catalogReferenceHigh: null,
+      sourceReferenceText: null,
+      referenceOrigin: "catalog" as const,
+      referenceDivergesFromCatalog: false,
       takenAt: "2026-04-21T08:00:00.000Z",
       count: 1,
     },
@@ -137,6 +147,11 @@ describe("lab-result FHIR Observations", () => {
             unit: "mg/L",
             referenceLow: null,
             referenceHigh: null,
+            catalogReferenceLow: null,
+            catalogReferenceHigh: null,
+            sourceReferenceText: null,
+            referenceOrigin: "catalog" as const,
+            referenceDivergesFromCatalog: false,
             takenAt: "2026-04-22T08:00:00.000Z",
             count: 1,
           },
@@ -178,6 +193,11 @@ describe("lab-result LOINC + canonical UCUM coding (v1.18.8)", () => {
             unit,
             referenceLow: null,
             referenceHigh: null,
+            catalogReferenceLow: null,
+            catalogReferenceHigh: null,
+            sourceReferenceText: null,
+            referenceOrigin: "catalog" as const,
+            referenceDivergesFromCatalog: false,
             takenAt: "2026-04-20T08:00:00.000Z",
             count: 1,
           },
@@ -264,6 +284,11 @@ describe("qualitative lab-result FHIR Observations (v1.18.9)", () => {
             unit: "",
             referenceLow: null,
             referenceHigh: null,
+            catalogReferenceLow: null,
+            catalogReferenceHigh: null,
+            sourceReferenceText: null,
+            referenceOrigin: "catalog" as const,
+            referenceDivergesFromCatalog: false,
             takenAt: "2026-04-20T08:00:00.000Z",
             count: 1,
           },
diff --git a/src/lib/fhir/resources/labs.ts b/src/lib/fhir/resources/labs.ts
index a02a82228..43509310a 100644
--- a/src/lib/fhir/resources/labs.ts
+++ b/src/lib/fhir/resources/labs.ts
@@ -7,8 +7,15 @@
  * `code.text` for the common biomarkers, and stamps the canonical UCUM `code`
  * on the value WHEN the recorded unit matches the mapped canonical symbol. An
  * analyte that does NOT resolve keeps the honest text-only `code` +
- * display-only `unit` (no fabricated terminology). The lab's reference bounds
- * map onto R4 `referenceRange`.
+ * display-only `unit` (no fabricated terminology).
+ *
+ * The reference bounds map onto R4 `referenceRange`, and they are the SAME
+ * bounds the app's own verdict uses: the window the reading's source report
+ * printed when it carries one, the catalog band otherwise, already resolved
+ * upstream in `loadLabResults`. When the source report stated its window in
+ * words the bounds could not be read from ("negativ", "siehe Befund"), that
+ * string rides on `referenceRange.text` so a receiver still gets what the lab
+ * wrote rather than a silently empty element.
  */
 import type { DoctorReportData } from "@/lib/doctor-report-data";
 import { LOINC_SYSTEM, UCUM_SYSTEM } from "@/lib/fhir/loinc-map";
@@ -82,8 +89,11 @@ export function labObservations(
     // The bounds are stated in the SAME unit as the value, so they carry the
     // SAME coding — a bare unit beside a coded value leaves a receiver unable
     // to compare the two.
+    const sourceText =
+      lab.referenceOrigin === "source" ? lab.sourceReferenceText : null;
+    const hasBounds = lab.referenceLow !== null || lab.referenceHigh !== null;
     const referenceRange: FhirObservationReferenceRange[] | undefined =
-      lab.referenceLow !== null || lab.referenceHigh !== null
+      hasBounds || sourceText
         ? [
             {
               ...(lab.referenceLow !== null
@@ -92,6 +102,7 @@ export function labObservations(
               ...(lab.referenceHigh !== null
                 ? { high: quantity(lab.referenceHigh) }
                 : {}),
+              ...(sourceText ? { text: sourceText } : {}),
             },
           ]
         : undefined;
diff --git a/src/lib/fhir/types.ts b/src/lib/fhir/types.ts
index 50b2be4fd..00e85cc95 100644
--- a/src/lib/fhir/types.ts
+++ b/src/lib/fhir/types.ts
@@ -117,6 +117,13 @@ export interface FhirObservation {
 export interface FhirObservationReferenceRange {
   low?: FhirQuantity;
   high?: FhirQuantity;
+  /**
+   * R4 `referenceRange.text`. Carries the window the source report printed,
+   * verbatim, when the reading has one. A receiver that cannot use the bounds
+   * (because the report stated a qualitative window like "negativ", or a
+   * one-sided one) still reads what the lab wrote.
+   */
+  text?: string;
 }
 
 export interface FhirDosage {
diff --git a/src/lib/fitbit/__tests__/sync-plausibility.test.ts b/src/lib/fitbit/__tests__/sync-plausibility.test.ts
new file mode 100644
index 000000000..7efe59f99
--- /dev/null
+++ b/src/lib/fitbit/__tests__/sync-plausibility.test.ts
@@ -0,0 +1,179 @@
+/**
+ * `upsertFitbitMeasurements` is the single write seam for every Fitbit
+ * resource leg — activity, sleep, daily metrics — and it holds Prisma
+ * directly, so it does not inherit the shared reconciler's gate. These cases
+ * pin that the provider's numbers clear the app's own declared plausibility
+ * band before any of them can become a row, and that a refusal is reported.
+ */
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+const { findManyMock, createManyMock, updateMock } = vi.hoisted(() => ({
+  findManyMock: vi.fn(async () => [] as unknown[]),
+  createManyMock: vi.fn<
+    () => Promise<Array<{ id: string; type: string; measuredAt: Date }>>
+  >(async () => []),
+  updateMock: vi.fn(async () => ({})),
+}));
+
+vi.mock("@/lib/db", () => ({
+  prisma: {
+    measurement: {
+      findMany: findManyMock,
+      createManyAndReturn: createManyMock,
+      update: updateMock,
+    },
+  },
+}));
+vi.mock("@/lib/crypto", () => ({ encrypt: vi.fn(), decrypt: vi.fn() }));
+vi.mock("@/lib/integrations/status", () => ({
+  isReauthRequired: vi.fn(async () => false),
+  recordSyncFailure: vi.fn(async () => {}),
+  recordSyncSuccess: vi.fn(async () => {}),
+}));
+vi.mock("@/lib/rollups/measurement-rollups", () => ({
+  collapseToTypeDayKeys: vi.fn(() => []),
+  recomputeBucketsForMeasurement: vi.fn(async () => {}),
+  recomputeUserRollups: vi.fn(async () => {}),
+}));
+vi.mock("@/lib/insights/comprehensive-generate", () => ({
+  invalidateStatusInsightsForTypes: vi.fn(async () => {}),
+}));
+vi.mock("@/lib/integrations/oauth-refresh", () => ({
+  persistRotatedToken: vi.fn(async () => {}),
+}));
+vi.mock("../credentials", () => ({
+  getUserFitbitCredentials: vi.fn(async () => null),
+}));
+vi.mock("../client", () => ({ refreshAccessToken: vi.fn() }));
+
+import { eventStorage } from "@/lib/logging/context";
+import { WideEventBuilder } from "@/lib/logging/event-builder";
+import { RANGE_REJECTED_META_KEY } from "@/lib/measurements/plausibility-gate";
+import type { RangeRejectionTally } from "@/lib/measurements/plausibility-gate";
+
+import { upsertFitbitMeasurements } from "../sync-core";
+
+/** RESTING_HEART_RATE is declared 25–220. */
+const REAL_READING = {
+  type: "RESTING_HEART_RATE",
+  value: 58,
+  unit: "bpm",
+  measuredAt: new Date("2026-07-08T00:00:00.000Z"),
+  externalId: "rhr:2026-07-08",
+};
+
+const IMPOSSIBLE_READING = {
+  type: "RESTING_HEART_RATE",
+  value: 4_915_200,
+  unit: "bpm",
+  measuredAt: new Date("2026-07-09T00:00:00.000Z"),
+  externalId: "rhr:2026-07-09",
+};
+
+let event: WideEventBuilder;
+
+function tally(): RangeRejectionTally | undefined {
+  return event.toJSON().meta?.[RANGE_REJECTED_META_KEY] as
+    RangeRejectionTally | undefined;
+}
+
+beforeEach(() => {
+  findManyMock.mockReset().mockResolvedValue([]);
+  createManyMock.mockReset().mockResolvedValue([]);
+  updateMock.mockReset().mockResolvedValue({});
+  event = new WideEventBuilder("background");
+});
+
+describe("upsertFitbitMeasurements — plausibility gate", () => {
+  it("writes a reading inside the metric's declared band", async () => {
+    createManyMock.mockResolvedValue([
+      {
+        id: "row-1",
+        type: "RESTING_HEART_RATE",
+        measuredAt: REAL_READING.measuredAt,
+      },
+    ]);
+
+    const result = await eventStorage.run(event, () =>
+      upsertFitbitMeasurements("user-1", [REAL_READING], { deferRollup: true }),
+    );
+
+    expect(result.imported).toBe(1);
+    const planned = (createManyMock.mock.calls[0] as unknown[])[0] as {
+      data: Array<{ value: number }>;
+    };
+    expect(planned.data).toHaveLength(1);
+    expect(planned.data[0]!.value).toBe(58);
+    expect(tally()).toBeUndefined();
+  });
+
+  it("refuses an out-of-band reading and annotates the drop", async () => {
+    createManyMock.mockResolvedValue([
+      {
+        id: "row-1",
+        type: "RESTING_HEART_RATE",
+        measuredAt: REAL_READING.measuredAt,
+      },
+    ]);
+
+    const result = await eventStorage.run(event, () =>
+      upsertFitbitMeasurements("user-1", [REAL_READING, IMPOSSIBLE_READING], {
+        deferRollup: true,
+      }),
+    );
+
+    expect(result.imported).toBe(1);
+    const planned = (createManyMock.mock.calls[0] as unknown[])[0] as {
+      data: Array<{ value: number; externalId: string }>;
+    };
+    expect(planned.data).toHaveLength(1);
+    expect(planned.data[0]!.externalId).toBe("rhr:2026-07-08");
+    // The refused reading never even reached the existence probe.
+    expect(
+      (
+        (findManyMock.mock.calls[0] as unknown[])[0] as {
+          where: { externalId: { in: string[] } };
+        }
+      ).where.externalId.in,
+    ).toEqual(["rhr:2026-07-08"]);
+    expect(tally()).toEqual({
+      total: 1,
+      buckets: [
+        {
+          source: "fitbit",
+          type: "RESTING_HEART_RATE",
+          direction: "above_max",
+          count: 1,
+        },
+      ],
+    });
+    expect(event.getLevel()).toBe("warn");
+  });
+
+  it("does not overwrite a stored reading with an out-of-band one", async () => {
+    // The key already exists; ungated, the update branch rewrote its value.
+    findManyMock.mockResolvedValue([
+      {
+        id: "existing",
+        type: "RESTING_HEART_RATE",
+        externalId: "rhr:2026-07-09",
+        value: 58,
+        unit: "bpm",
+        measuredAt: IMPOSSIBLE_READING.measuredAt,
+        sleepStage: null,
+        deletedAt: null,
+      },
+    ]);
+
+    const result = await eventStorage.run(event, () =>
+      upsertFitbitMeasurements("user-1", [IMPOSSIBLE_READING], {
+        deferRollup: true,
+      }),
+    );
+
+    expect(result.imported).toBe(0);
+    expect(updateMock).not.toHaveBeenCalled();
+    expect(createManyMock).not.toHaveBeenCalled();
+    expect(tally()?.total).toBe(1);
+  });
+});
diff --git a/src/lib/fitbit/sync-core.ts b/src/lib/fitbit/sync-core.ts
index 74637e01b..f67f4422b 100644
--- a/src/lib/fitbit/sync-core.ts
+++ b/src/lib/fitbit/sync-core.ts
@@ -15,6 +15,7 @@ import { persistRotatedToken } from "@/lib/integrations/oauth-refresh";
 import { recordSyncFailure } from "@/lib/integrations/status";
 import type { FailureKind } from "@/lib/integrations/status";
 import { getEvent } from "@/lib/logging/context";
+import { dropImplausibleMeasurements } from "@/lib/measurements/plausibility-gate";
 import {
   collapseToTypeDayKeys,
   recomputeBucketsForMeasurement,
@@ -530,7 +531,7 @@ export async function replaceStaleFitbitSleep(
  */
 export async function upsertFitbitMeasurements(
   userId: string,
-  readings: FitbitMeasurementUpsert[],
+  incoming: FitbitMeasurementUpsert[],
   opts: { deferRollup?: boolean } = {},
 ): Promise<{
   imported: number;
@@ -541,6 +542,15 @@ export async function upsertFitbitMeasurements(
     measuredAt: Date;
   }>;
 }> {
+  // Every resource leg funnels through here, so this is the one place the
+  // provider's numbers have to clear the app's declared plausibility band
+  // before they can become rows. A refused reading is dropped and tallied on
+  // the ambient event, never clamped and never written for a later reader to
+  // discover.
+  const readings = dropImplausibleMeasurements("fitbit", incoming, (r) => ({
+    type: r.type,
+    value: r.value,
+  }));
   if (readings.length === 0) return { imported: 0, touched: [], inserted: [] };
 
   // Probe EVERY existing row (live AND tombstoned) for the batch's externalIds
diff --git a/src/lib/google-health/__tests__/sync-plausibility.test.ts b/src/lib/google-health/__tests__/sync-plausibility.test.ts
new file mode 100644
index 000000000..2fb5b3404
--- /dev/null
+++ b/src/lib/google-health/__tests__/sync-plausibility.test.ts
@@ -0,0 +1,180 @@
+/**
+ * `upsertGoogleHealthMeasurements` is the single write seam for every Google
+ * Health resource leg and it holds Prisma directly, so it does not inherit the
+ * shared reconciler's gate. These cases pin that the provider's numbers clear
+ * the app's own declared plausibility band before any of them can become a
+ * row, and that a refusal is reported rather than swallowed.
+ */
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+const { findManyMock, createManyMock, updateMock } = vi.hoisted(() => ({
+  findManyMock: vi.fn(async () => [] as unknown[]),
+  createManyMock: vi.fn<
+    () => Promise<Array<{ id: string; type: string; measuredAt: Date }>>
+  >(async () => []),
+  updateMock: vi.fn(async () => ({})),
+}));
+
+vi.mock("@/lib/db", () => ({
+  prisma: {
+    measurement: {
+      findMany: findManyMock,
+      createManyAndReturn: createManyMock,
+      update: updateMock,
+    },
+  },
+}));
+vi.mock("@/lib/crypto", () => ({ encrypt: vi.fn(), decrypt: vi.fn() }));
+vi.mock("@/lib/integrations/status", () => ({
+  isReauthRequired: vi.fn(async () => false),
+  recordSyncFailure: vi.fn(async () => {}),
+  recordSyncSuccess: vi.fn(async () => {}),
+}));
+vi.mock("@/lib/rollups/measurement-rollups", () => ({
+  collapseToTypeDayKeys: vi.fn(() => []),
+  recomputeBucketsForMeasurement: vi.fn(async () => {}),
+  recomputeUserRollups: vi.fn(async () => {}),
+}));
+vi.mock("@/lib/insights/comprehensive-generate", () => ({
+  invalidateStatusInsightsForTypes: vi.fn(async () => {}),
+}));
+vi.mock("../credentials", () => ({
+  getUserGoogleHealthCredentials: vi.fn(async () => null),
+}));
+vi.mock("../client", async () => {
+  const actual = await vi.importActual<typeof import("../client")>("../client");
+  return {
+    ...actual,
+    refreshAccessToken: vi.fn(),
+    noteGoogleHealthMapped: vi.fn(),
+    noteGoogleHealthWritten: vi.fn(),
+    noteGoogleHealthOutcomeFailure: vi.fn(),
+  };
+});
+
+import { eventStorage } from "@/lib/logging/context";
+import { WideEventBuilder } from "@/lib/logging/event-builder";
+import { RANGE_REJECTED_META_KEY } from "@/lib/measurements/plausibility-gate";
+import type { RangeRejectionTally } from "@/lib/measurements/plausibility-gate";
+
+import { upsertGoogleHealthMeasurements } from "../sync-core";
+
+/** OXYGEN_SATURATION is declared 50–100. */
+const REAL_READING = {
+  type: "OXYGEN_SATURATION",
+  value: 97,
+  unit: "%",
+  measuredAt: new Date("2026-07-08T00:00:00.000Z"),
+  externalId: "spo2:2026-07-08",
+};
+
+const IMPOSSIBLE_READING = {
+  type: "OXYGEN_SATURATION",
+  value: 9_700,
+  unit: "%",
+  measuredAt: new Date("2026-07-09T00:00:00.000Z"),
+  externalId: "spo2:2026-07-09",
+};
+
+let event: WideEventBuilder;
+
+function tally(): RangeRejectionTally | undefined {
+  return event.toJSON().meta?.[RANGE_REJECTED_META_KEY] as
+    RangeRejectionTally | undefined;
+}
+
+beforeEach(() => {
+  findManyMock.mockReset().mockResolvedValue([]);
+  createManyMock.mockReset().mockResolvedValue([]);
+  updateMock.mockReset().mockResolvedValue({});
+  event = new WideEventBuilder("background");
+});
+
+describe("upsertGoogleHealthMeasurements — plausibility gate", () => {
+  it("writes a reading inside the metric's declared band", async () => {
+    createManyMock.mockResolvedValue([
+      {
+        id: "row-1",
+        type: "OXYGEN_SATURATION",
+        measuredAt: REAL_READING.measuredAt,
+      },
+    ]);
+
+    const result = await eventStorage.run(event, () =>
+      upsertGoogleHealthMeasurements("user-1", [REAL_READING], {
+        deferRollup: true,
+      }),
+    );
+
+    expect(result.imported).toBe(1);
+    const planned = (createManyMock.mock.calls[0] as unknown[])[0] as {
+      data: Array<{ value: number }>;
+    };
+    expect(planned.data).toHaveLength(1);
+    expect(planned.data[0]!.value).toBe(97);
+    expect(tally()).toBeUndefined();
+  });
+
+  it("refuses an out-of-band reading and annotates the drop", async () => {
+    createManyMock.mockResolvedValue([
+      {
+        id: "row-1",
+        type: "OXYGEN_SATURATION",
+        measuredAt: REAL_READING.measuredAt,
+      },
+    ]);
+
+    const result = await eventStorage.run(event, () =>
+      upsertGoogleHealthMeasurements(
+        "user-1",
+        [REAL_READING, IMPOSSIBLE_READING],
+        { deferRollup: true },
+      ),
+    );
+
+    expect(result.imported).toBe(1);
+    const planned = (createManyMock.mock.calls[0] as unknown[])[0] as {
+      data: Array<{ externalId: string }>;
+    };
+    expect(planned.data).toHaveLength(1);
+    expect(planned.data[0]!.externalId).toBe("spo2:2026-07-08");
+    expect(tally()).toEqual({
+      total: 1,
+      buckets: [
+        {
+          source: "googleHealth",
+          type: "OXYGEN_SATURATION",
+          direction: "above_max",
+          count: 1,
+        },
+      ],
+    });
+    expect(event.getLevel()).toBe("warn");
+  });
+
+  it("does not overwrite a stored reading with an out-of-band one", async () => {
+    findManyMock.mockResolvedValue([
+      {
+        id: "existing",
+        type: "OXYGEN_SATURATION",
+        externalId: "spo2:2026-07-09",
+        value: 97,
+        unit: "%",
+        measuredAt: IMPOSSIBLE_READING.measuredAt,
+        sleepStage: null,
+        deletedAt: null,
+      },
+    ]);
+
+    const result = await eventStorage.run(event, () =>
+      upsertGoogleHealthMeasurements("user-1", [IMPOSSIBLE_READING], {
+        deferRollup: true,
+      }),
+    );
+
+    expect(result.imported).toBe(0);
+    expect(updateMock).not.toHaveBeenCalled();
+    expect(createManyMock).not.toHaveBeenCalled();
+    expect(tally()?.total).toBe(1);
+  });
+});
diff --git a/src/lib/google-health/sync-core.ts b/src/lib/google-health/sync-core.ts
index 27ccaa139..d0545ee0d 100644
--- a/src/lib/google-health/sync-core.ts
+++ b/src/lib/google-health/sync-core.ts
@@ -20,6 +20,7 @@ import { prisma } from "@/lib/db";
 import type { MeasurementType } from "@/generated/prisma/client";
 import { encrypt, decrypt } from "@/lib/crypto";
 import { getEvent } from "@/lib/logging/context";
+import { dropImplausibleMeasurements } from "@/lib/measurements/plausibility-gate";
 import { emitInsertedMeasurementArrivals } from "@/lib/arrivals/measurement-emit";
 import { recordSyncFailure, type FailureKind } from "@/lib/integrations/status";
 import {
@@ -487,7 +488,7 @@ export async function replaceStaleGoogleHealthSleep(
  */
 export async function upsertGoogleHealthMeasurements(
   userId: string,
-  readings: GoogleHealthMeasurementUpsert[],
+  incoming: GoogleHealthMeasurementUpsert[],
   opts: { deferRollup?: boolean } = {},
 ): Promise<{
   imported: number;
@@ -498,7 +499,17 @@ export async function upsertGoogleHealthMeasurements(
     measuredAt: Date;
   }>;
 }> {
-  noteGoogleHealthMapped(readings.length);
+  noteGoogleHealthMapped(incoming.length);
+  // Every resource leg funnels through here, so this is the one place the
+  // provider's numbers have to clear the app's declared plausibility band
+  // before they can become rows. A refused reading is dropped and tallied on
+  // the ambient event, never clamped and never written for a later reader to
+  // discover.
+  const readings = dropImplausibleMeasurements(
+    "googleHealth",
+    incoming,
+    (r) => ({ type: r.type, value: r.value }),
+  );
   if (readings.length === 0) return { imported: 0, touched: [], inserted: [] };
 
   // Probe EVERY existing row (live AND tombstoned) for the batch's externalIds
diff --git a/src/lib/insights/__tests__/labs-changes.test.ts b/src/lib/insights/__tests__/labs-changes.test.ts
index f3a3e5ddd..0c3d8085c 100644
--- a/src/lib/insights/__tests__/labs-changes.test.ts
+++ b/src/lib/insights/__tests__/labs-changes.test.ts
@@ -19,7 +19,14 @@ function row(
   analyte: string,
   value: number,
   day: string,
-  opts: { unit?: string; low?: number | null; high?: number | null } = {},
+  opts: {
+    unit?: string;
+    low?: number | null;
+    high?: number | null;
+    sourceLow?: number | null;
+    sourceHigh?: number | null;
+    sourceText?: string | null;
+  } = {},
 ): LabChangeRow {
   return {
     analyte,
@@ -27,6 +34,9 @@ function row(
     value,
     referenceLow: opts.low ?? null,
     referenceHigh: opts.high ?? null,
+    sourceReferenceLow: opts.sourceLow ?? null,
+    sourceReferenceHigh: opts.sourceHigh ?? null,
+    sourceReferenceText: opts.sourceText ?? null,
     takenAt: new Date(`${day}T08:00:00.000Z`),
   };
 }
diff --git a/src/lib/insights/biomarker-status.ts b/src/lib/insights/biomarker-status.ts
index 29f2214ce..3dc089afd 100644
--- a/src/lib/insights/biomarker-status.ts
+++ b/src/lib/insights/biomarker-status.ts
@@ -29,7 +29,10 @@ import {
 } from "@/lib/ai/prompts/biomarker";
 import { openerArchetypeHint } from "@/lib/ai/prompts/opener-archetype";
 import type { Locale } from "@/lib/i18n/config";
-import { classifyReferenceRange } from "@/lib/labs/reference-range";
+import {
+  classifyAgainstEffectiveRange,
+  resolveEffectiveReferenceRange,
+} from "@/lib/labs/reference-range";
 import { getNoKeyBiomarkerStatusText } from "@/lib/insights/no-key-fallbacks";
 import { hashInsightSnapshot } from "@/lib/insights/snapshot-hash";
 import { runStatusCompletion } from "@/lib/insights/status-provider";
@@ -158,7 +161,17 @@ export async function generateBiomarkerStatus(args: {
     },
     orderBy: { takenAt: "desc" },
     take: SNAPSHOT_READING_CAP,
-    select: { id: true, value: true, takenAt: true },
+    select: {
+      id: true,
+      value: true,
+      takenAt: true,
+      // The window this reading's own report printed, when it carries one.
+      // The verdict below is the reading's, not the marker's, so it has to
+      // read the reading's window — see `resolveEffectiveReferenceRange`.
+      sourceReferenceLow: true,
+      sourceReferenceHigh: true,
+      sourceReferenceText: true,
+    },
   });
   if (rows.length === 0) {
     annotate({
@@ -174,6 +187,14 @@ export async function generateBiomarkerStatus(args: {
     takenAt: r.takenAt,
   }));
   const latest = readings[0];
+  // The window the latest reading is judged against: its own report's range
+  // when that reading carries one, the catalog band otherwise. One rule, the
+  // same one the API DTO, the doctor report and the coach snapshot apply.
+  const latestRange = resolveEffectiveReferenceRange(
+    marker.lowerBound,
+    marker.upperBound,
+    rows[0],
+  );
   const totalCount = await prisma.labResult.count({
     where: {
       userId: args.userId,
@@ -226,7 +247,7 @@ export async function generateBiomarkerStatus(args: {
     locale,
     promptVersion: PROMPT_VERSION,
     count: totalCount,
-    bounds: { lower: marker.lowerBound, upper: marker.upperBound },
+    bounds: { lower: latestRange.low, upper: latestRange.high },
     latest: {
       id: latest.id,
       takenAt: latest.takenAt.toISOString(),
@@ -252,11 +273,7 @@ export async function generateBiomarkerStatus(args: {
   // Ascending series (oldest → newest) for the trend summary the prompt reads.
   const ascending = [...readings].reverse();
   const summary = summarizeSeries(ascending.map((r) => ({ value: r.value })));
-  const latestStatus = classifyReferenceRange(
-    latest.value,
-    marker.lowerBound,
-    marker.upperBound,
-  );
+  const latestStatus = classifyAgainstEffectiveRange(latest.value, latestRange);
 
   const snapshot = {
     locale,
@@ -266,8 +283,8 @@ export async function generateBiomarkerStatus(args: {
       name: marker.name,
       unit: marker.unit,
       referenceRange:
-        marker.lowerBound != null || marker.upperBound != null
-          ? { lower: marker.lowerBound, upper: marker.upperBound }
+        latestRange.low != null || latestRange.high != null
+          ? { lower: latestRange.low, upper: latestRange.high }
           : null,
     },
     dataCoverage: {
diff --git a/src/lib/insights/correlation-channel-series.ts b/src/lib/insights/correlation-channel-series.ts
index 97f5dd940..caac368f2 100644
--- a/src/lib/insights/correlation-channel-series.ts
+++ b/src/lib/insights/correlation-channel-series.ts
@@ -590,6 +590,9 @@ export async function fetchLabDraws(
       unit: true,
       referenceLow: true,
       referenceHigh: true,
+      sourceReferenceLow: true,
+      sourceReferenceHigh: true,
+      sourceReferenceText: true,
       panel: true,
       value: true,
       takenAt: true,
diff --git a/src/lib/insights/feature-blocks.ts b/src/lib/insights/feature-blocks.ts
index b8dc18b35..ba63d860c 100644
--- a/src/lib/insights/feature-blocks.ts
+++ b/src/lib/insights/feature-blocks.ts
@@ -10,7 +10,7 @@
  * point (`extractFeatures`) stays in the hub.
  */
 import { prisma } from "@/lib/db";
-import { classifyReferenceRange } from "@/lib/labs/reference-range";
+import { classifyAgainstEffectiveRange } from "@/lib/labs/reference-range";
 import { calendarDaysUntil } from "@/lib/measurement-reminders/due-day";
 import { resolveLabFields } from "@/lib/labs/serialise";
 import { readRollupBuckets } from "@/lib/rollups/measurement-rollups";
@@ -164,6 +164,9 @@ export async function readLabsBriefingBlock(
       valueText: true,
       referenceLow: true,
       referenceHigh: true,
+      sourceReferenceLow: true,
+      sourceReferenceHigh: true,
+      sourceReferenceText: true,
       takenAt: true,
       biomarkerId: true,
       biomarker: {
@@ -198,14 +201,10 @@ export async function readLabsBriefingBlock(
   for (const list of byMarker.values()) {
     const latest = list[0];
     const resolved = resolveLabFields(latest, latest.biomarker);
-    const rangeStatus =
-      latest.value === null
-        ? ("unknown" as const)
-        : classifyReferenceRange(
-            latest.value,
-            resolved.referenceLow,
-            resolved.referenceHigh,
-          );
+    const rangeStatus = classifyAgainstEffectiveRange(
+      latest.value,
+      resolved.effectiveRange,
+    );
 
     // Trend = latest numeric reading vs the immediately prior numeric reading.
     let trend: "rising" | "falling" | "flat" | null = null;
diff --git a/src/lib/insights/labs-changes.ts b/src/lib/insights/labs-changes.ts
index 6486e2b15..a16ea22cc 100644
--- a/src/lib/insights/labs-changes.ts
+++ b/src/lib/insights/labs-changes.ts
@@ -4,9 +4,11 @@
  * Groups the user's numeric lab results by panel DATE (the calendar day of
  * `takenAt`, UTC), finds the two most-recent dates, and for every analyte that
  * appears in BOTH the latest and the previous panel reports the signed delta,
- * the direction, and where the latest value sits against its reference band
- * (`classifyReferenceRange`). Qualitative (valueText-only) results carry no
- * numeric value, so they are skipped — a delta is meaningless for them.
+ * the direction, and where the latest value sits against the reference window
+ * in force for it — the range that reading's own report printed when it has
+ * one, the catalog band otherwise, resolved through the shared
+ * `resolveEffectiveReferenceRange`. Qualitative (valueText-only) results carry
+ * no numeric value, so they are skipped — a delta is meaningless for them.
  *
  * Pure + Prisma-free so the present / absent states are unit-testable: it is
  * absent when there are fewer than two panel dates, no analyte is shared, or
@@ -14,12 +16,14 @@
  * only — a delta is not a diagnosis.
  */
 import {
-  classifyReferenceRange,
+  classifyAgainstEffectiveRange,
+  resolveEffectiveReferenceRange,
   type ReferenceRangeStatus,
+  type SourceReferenceRange,
 } from "@/lib/labs/reference-range";
 
-/** A single numeric lab reading. */
-export interface LabChangeRow {
+/** A single numeric lab reading, with both windows it could be judged against. */
+export interface LabChangeRow extends SourceReferenceRange {
   analyte: string;
   unit: string;
   value: number;
@@ -150,10 +154,13 @@ export function summariseLabChanges(
       previous: previousRow.value,
       delta,
       direction,
-      status: classifyReferenceRange(
+      status: classifyAgainstEffectiveRange(
         latestRow.value,
-        latestRow.referenceLow,
-        latestRow.referenceHigh,
+        resolveEffectiveReferenceRange(
+          latestRow.referenceLow,
+          latestRow.referenceHigh,
+          latestRow,
+        ),
       ),
     });
   }
diff --git a/src/lib/labs/__tests__/effective-reference-range.test.ts b/src/lib/labs/__tests__/effective-reference-range.test.ts
new file mode 100644
index 000000000..92dc9721b
--- /dev/null
+++ b/src/lib/labs/__tests__/effective-reference-range.test.ts
@@ -0,0 +1,128 @@
+import { describe, expect, it } from "vitest";
+
+import {
+  classifyAgainstEffectiveRange,
+  resolveEffectiveReferenceRange,
+} from "@/lib/labs/reference-range";
+
+const NO_SOURCE = {
+  sourceReferenceLow: null,
+  sourceReferenceHigh: null,
+  sourceReferenceText: null,
+};
+
+describe("resolveEffectiveReferenceRange", () => {
+  it("falls back to the catalog band when the reading carries no source window", () => {
+    const eff = resolveEffectiveReferenceRange(3.5, 5, NO_SOURCE);
+    expect(eff).toMatchObject({
+      low: 3.5,
+      high: 5,
+      origin: "catalog",
+      catalogLow: 3.5,
+      catalogHigh: 5,
+      sourceText: null,
+      divergesFromCatalog: false,
+    });
+  });
+
+  it("reports no window when neither side states one", () => {
+    expect(resolveEffectiveReferenceRange(null, null, NO_SOURCE)).toMatchObject(
+      { low: null, high: null, origin: "none", divergesFromCatalog: false },
+    );
+  });
+
+  it("lets the source window win over the catalog band for that reading", () => {
+    const eff = resolveEffectiveReferenceRange(3.5, 5, {
+      sourceReferenceLow: 3.9,
+      sourceReferenceHigh: 5.4,
+      sourceReferenceText: "3,9 - 5,4",
+    });
+    expect(eff).toMatchObject({
+      low: 3.9,
+      high: 5.4,
+      origin: "source",
+      catalogLow: 3.5,
+      catalogHigh: 5,
+      sourceText: "3,9 - 5,4",
+      divergesFromCatalog: true,
+    });
+  });
+
+  it("does not call an identical window a divergence", () => {
+    const eff = resolveEffectiveReferenceRange(3.5, 5, {
+      sourceReferenceLow: 3.5,
+      sourceReferenceHigh: 5,
+      sourceReferenceText: "3,5 - 5,0",
+    });
+    expect(eff.origin).toBe("source");
+    expect(eff.divergesFromCatalog).toBe(false);
+  });
+
+  it("takes a one-sided source window whole, not merged with the catalog", () => {
+    // A report that prints "< 5" states a ceiling and NO floor. Borrowing the
+    // catalog's floor would invent a window the report never stated.
+    const eff = resolveEffectiveReferenceRange(3.5, 5, {
+      sourceReferenceLow: null,
+      sourceReferenceHigh: 4.2,
+      sourceReferenceText: "< 4,2",
+    });
+    expect(eff).toMatchObject({
+      low: null,
+      high: 4.2,
+      origin: "source",
+      divergesFromCatalog: true,
+    });
+  });
+
+  it("does not displace the catalog for a printed window with no derivable bound", () => {
+    // "negativ" is carried through verbatim, but it is not an argument for
+    // discarding the catalog band.
+    const eff = resolveEffectiveReferenceRange(3.5, 5, {
+      sourceReferenceLow: null,
+      sourceReferenceHigh: null,
+      sourceReferenceText: "negativ",
+    });
+    expect(eff).toMatchObject({
+      low: 3.5,
+      high: 5,
+      origin: "catalog",
+      sourceText: "negativ",
+      divergesFromCatalog: false,
+    });
+  });
+
+  it("reports a source window as no divergence when the catalog has none", () => {
+    const eff = resolveEffectiveReferenceRange(null, null, {
+      sourceReferenceLow: 3.9,
+      sourceReferenceHigh: 5.4,
+      sourceReferenceText: "3,9 - 5,4",
+    });
+    expect(eff.origin).toBe("source");
+    expect(eff.divergesFromCatalog).toBe(false);
+  });
+});
+
+describe("classifyAgainstEffectiveRange", () => {
+  it("judges a reading by the source window, not the catalog band", () => {
+    // 5.2 sits inside the catalog band (3.5–5.0 would call it high) but the
+    // report that produced this value states 3.9–5.4, so it is in range.
+    const eff = resolveEffectiveReferenceRange(3.5, 5, {
+      sourceReferenceLow: 3.9,
+      sourceReferenceHigh: 5.4,
+      sourceReferenceText: "3,9 - 5,4",
+    });
+    expect(classifyAgainstEffectiveRange(5.2, eff)).toBe("in-range");
+    expect(classifyAgainstEffectiveRange(3.7, eff)).toBe("below");
+    expect(classifyAgainstEffectiveRange(5.5, eff)).toBe("above");
+  });
+
+  it("keeps the catalog verdict for a reading with no source window", () => {
+    const eff = resolveEffectiveReferenceRange(3.5, 5, NO_SOURCE);
+    expect(classifyAgainstEffectiveRange(5.2, eff)).toBe("above");
+  });
+
+  it("never classifies a qualitative reading", () => {
+    const eff = resolveEffectiveReferenceRange(3.5, 5, NO_SOURCE);
+    expect(classifyAgainstEffectiveRange(null, eff)).toBe("unknown");
+  });
+});
diff --git a/src/lib/labs/__tests__/parse-reference-range.test.ts b/src/lib/labs/__tests__/parse-reference-range.test.ts
new file mode 100644
index 000000000..d70e32fcf
--- /dev/null
+++ b/src/lib/labs/__tests__/parse-reference-range.test.ts
@@ -0,0 +1,219 @@
+import { describe, expect, it } from "vitest";
+
+import { parseReferenceRange } from "@/lib/labs/parse-reference-range";
+
+/**
+ * Real-shaped strings, taken from the notation German and English lab reports
+ * actually print. The parser's contract is asymmetric on purpose: deriving a
+ * bound is best-effort, KEEPING the printed string is mandatory. Every case
+ * below therefore asserts the verbatim text survives, and only the cases that
+ * can be read without guessing assert bounds.
+ */
+describe("parseReferenceRange — two-sided windows", () => {
+  it.each([
+    ["3.5-5.0", 3.5, 5],
+    ["3,5-5,0", 3.5, 5],
+    ["3.5 - 5.0", 3.5, 5],
+    ["3,5 – 5,0", 3.5, 5],
+    ["3,5 — 5,0", 3.5, 5],
+    ["3,5 bis 5,0", 3.5, 5],
+    ["3.5 to 5.0", 3.5, 5],
+    ["3,5 ... 5,0", 3.5, 5],
+    ["3,5 .. 5,0", 3.5, 5],
+    ["von 3,5 bis 5,0", 3.5, 5],
+    ["[3,5 - 5,0]", 3.5, 5],
+    ["(3.5-5.0)", 3.5, 5],
+  ])("reads %s as %s..%s", (raw, low, high) => {
+    const parsed = parseReferenceRange(raw);
+    expect(parsed).toEqual({ low, high, text: raw.trim() });
+  });
+
+  it("reads a negative lower bound (base excess prints one)", () => {
+    expect(parseReferenceRange("-2,0 bis +3,0")).toEqual({
+      low: -2,
+      high: 3,
+      text: "-2,0 bis +3,0",
+    });
+  });
+
+  it("reads a German thousands separator as one number, not a decimal", () => {
+    // Platelets print as "150.000 - 400.000 /µl" on a German report. Reading
+    // the dot as a decimal point would yield a 150–400 window and silently
+    // flag every normal count as wildly high.
+    expect(parseReferenceRange("150.000 - 400.000")).toEqual({
+      low: 150000,
+      high: 400000,
+      text: "150.000 - 400.000",
+    });
+  });
+
+  it("reads an English thousands separator", () => {
+    expect(parseReferenceRange("150,000 - 400,000")).toEqual({
+      low: 150000,
+      high: 400000,
+      text: "150,000 - 400,000",
+    });
+  });
+
+  it("refuses a transposed window rather than swapping it", () => {
+    // Swapping would be a guess about which digit the lab meant to print.
+    expect(parseReferenceRange("5,0 - 3,5")).toEqual({
+      low: null,
+      high: null,
+      text: "5,0 - 3,5",
+    });
+  });
+});
+
+describe("parseReferenceRange — one-sided windows", () => {
+  it.each([
+    ["< 5", 5],
+    ["<5,0", 5],
+    ["≤ 5", 5],
+    ["<= 5", 5],
+    ["bis 5,0", 5],
+    ["bis zu 5,0", 5],
+    ["max. 5,0", 5],
+    ["max 5", 5],
+    ["kleiner 5", 5],
+    ["unter 5", 5],
+    ["up to 5.0", 5],
+  ])("reads %s as an upper bound of %s", (raw, high) => {
+    expect(parseReferenceRange(raw)).toEqual({
+      low: null,
+      high,
+      text: raw.trim(),
+    });
+  });
+
+  it.each([
+    ["> 3.5", 3.5],
+    [">3,5", 3.5],
+    ["≥ 3,5", 3.5],
+    [">= 3.5", 3.5],
+    ["ab 3,5", 3.5],
+    ["min. 3,5", 3.5],
+    ["mind. 3,5", 3.5],
+    ["mindestens 3,5", 3.5],
+    ["größer 3,5", 3.5],
+    ["groesser 3,5", 3.5],
+    ["über 3,5", 3.5],
+  ])("reads %s as a lower bound of %s", (raw, low) => {
+    expect(parseReferenceRange(raw)).toEqual({
+      low,
+      high: null,
+      text: raw.trim(),
+    });
+  });
+});
+
+describe("parseReferenceRange — units", () => {
+  it("reads a window that carries the reading's own unit", () => {
+    expect(parseReferenceRange("3,5 - 5,0 mmol/l", "mmol/L")).toEqual({
+      low: 3.5,
+      high: 5,
+      text: "3,5 - 5,0 mmol/l",
+    });
+  });
+
+  it("reads a trailing unit when the caller states none", () => {
+    expect(parseReferenceRange("0,5 - 1,2 mg/dl")).toEqual({
+      low: 0.5,
+      high: 1.2,
+      text: "0,5 - 1,2 mg/dl",
+    });
+  });
+
+  it("refuses bounds when the printed unit contradicts the reading's unit", () => {
+    // Converting mmol/L into mg/dL is interpretation and needs an analyte-
+    // specific factor. Keeping the string and no bounds is the honest answer.
+    const parsed = parseReferenceRange("3,5 - 5,0 mmol/l", "mg/dL");
+    expect(parsed).toEqual({
+      low: null,
+      high: null,
+      text: "3,5 - 5,0 mmol/l",
+    });
+  });
+
+  it("matches units case- and space-insensitively", () => {
+    expect(parseReferenceRange("< 5 MG/DL", "mg/dl")).toEqual({
+      low: null,
+      high: 5,
+      text: "< 5 MG/DL",
+    });
+  });
+
+  it("tolerates a percent window against a percent reading", () => {
+    expect(parseReferenceRange("4,0 - 6,0 %", "%")).toEqual({
+      low: 4,
+      high: 6,
+      text: "4,0 - 6,0 %",
+    });
+  });
+});
+
+describe("parseReferenceRange — text the parser must not invent bounds for", () => {
+  it.each([
+    "negativ",
+    "negative",
+    "nicht nachweisbar",
+    "siehe Befund",
+    "n.n.",
+    "unauffällig",
+    "altersabhängig",
+    "methodenabhängig",
+  ])("keeps %s verbatim with no bounds", (raw) => {
+    expect(parseReferenceRange(raw)).toEqual({
+      low: null,
+      high: null,
+      text: raw,
+    });
+  });
+
+  it("keeps a bare number verbatim without treating it as a bound", () => {
+    // "5,0" alone states neither a ceiling nor a floor; picking one would be
+    // the parser deciding what the report meant.
+    expect(parseReferenceRange("5,0")).toEqual({
+      low: null,
+      high: null,
+      text: "5,0",
+    });
+  });
+
+  it("keeps a three-number string verbatim", () => {
+    expect(parseReferenceRange("3,5 - 5,0 - 7,0")).toEqual({
+      low: null,
+      high: null,
+      text: "3,5 - 5,0 - 7,0",
+    });
+  });
+
+  it("caps an over-long string rather than storing a whole paragraph", () => {
+    const parsed = parseReferenceRange("x".repeat(500));
+    expect(parsed?.text).toHaveLength(120);
+    expect(parsed?.low).toBeNull();
+    expect(parsed?.high).toBeNull();
+  });
+
+  it("collapses internal whitespace so the stored string stays one line", () => {
+    expect(parseReferenceRange("  3,5\n\t-   5,0  ")).toEqual({
+      low: 3.5,
+      high: 5,
+      text: "3,5 - 5,0",
+    });
+  });
+});
+
+describe("parseReferenceRange — absence", () => {
+  it.each([null, undefined, "", "   "])("returns null for %s", (raw) => {
+    expect(parseReferenceRange(raw)).toBeNull();
+  });
+
+  it("refuses a non-finite bound", () => {
+    expect(parseReferenceRange("1e999 - 2e999")).toEqual({
+      low: null,
+      high: null,
+      text: "1e999 - 2e999",
+    });
+  });
+});
diff --git a/src/lib/labs/__tests__/serialise.test.ts b/src/lib/labs/__tests__/serialise.test.ts
index f2dd77cd2..4ee846f49 100644
--- a/src/lib/labs/__tests__/serialise.test.ts
+++ b/src/lib/labs/__tests__/serialise.test.ts
@@ -17,6 +17,9 @@ const baseRow: LabRow = {
   unit: "mg/dl", // lowercase legacy unit
   referenceLow: null,
   referenceHigh: 100, // stale per-row bound
+  sourceReferenceLow: null,
+  sourceReferenceHigh: null,
+  sourceReferenceText: null,
   takenAt: new Date("2026-01-01T08:00:00.000Z"),
   source: "MANUAL",
   biomarkerId: "bm_1",
diff --git a/src/lib/labs/ocr-extract.ts b/src/lib/labs/ocr-extract.ts
index 050e16f50..fcdb01563 100644
--- a/src/lib/labs/ocr-extract.ts
+++ b/src/lib/labs/ocr-extract.ts
@@ -24,6 +24,7 @@ import {
 } from "@/lib/ai/types";
 import { AI_BUDGETS } from "@/lib/ai/ai-budgets";
 import { prisma } from "@/lib/db";
+import { parseReferenceRange } from "@/lib/labs/parse-reference-range";
 import { annotate } from "@/lib/logging/context";
 import {
   extractedLabsSchema,
@@ -42,7 +43,8 @@ Extract every analyte reading you can read. For each reading capture:
 - value: the numeric result as a number, OR null if the result is qualitative text.
 - valueText: the qualitative result text (e.g. "negativ", "positiv", "nicht nachweisbar"), OR null if the result is numeric.
 - unit: the measurement unit (e.g. "mg/dL", "%", "ng/mL"), or null if none is printed or the reading is qualitative.
-- referenceLow / referenceHigh: the reference-range bounds as numbers, or null. A one-sided range like "< 116" sets referenceHigh only; "> 40" sets referenceLow only.
+- referenceText: the reference range EXACTLY as printed beside the value, verbatim and complete, including its operator and unit if written (for example "3,5 - 5,0", "< 116", "bis 5,0", "150.000 - 400.000 /\u00b5l", "negativ"). Copy the characters; do NOT reformat, convert, or normalise them. Null only when no range is printed for that row.
+- referenceLow / referenceHigh: the SAME range reduced to numbers, when it reduces to numbers, else null. A one-sided range like "< 116" sets referenceHigh only; "> 40" sets referenceLow only.
 - takenAt: the per-row collection date in ISO 8601 (YYYY-MM-DD) if a date is printed for that row, else null.
 - confidence: an object { analyte, value, unit, range } with a 0..1 score for how legible each field was. Use a low score when a field is blurred, ambiguous, or you had to guess.
 
@@ -51,7 +53,7 @@ Set EXACTLY ONE of value / valueText per reading. Never invent a value you canno
 Also capture reportDate: the report's collection/sample date in ISO 8601 (YYYY-MM-DD), or null.
 
 Respond ONLY with a JSON object of this exact shape:
-{ "reportDate": string|null, "rows": [ { "analyte": string, "value": number|null, "valueText": string|null, "unit": string|null, "referenceLow": number|null, "referenceHigh": number|null, "takenAt": string|null, "confidence": { "analyte": number, "value": number, "unit": number, "range": number } } ] }`;
+{ "reportDate": string|null, "rows": [ { "analyte": string, "value": number|null, "valueText": string|null, "unit": string|null, "referenceText": string|null, "referenceLow": number|null, "referenceHigh": number|null, "takenAt": string|null, "confidence": { "analyte": number, "value": number, "unit": number, "range": number } } ] }`;
 
 const USER_PROMPT = `Transcribe the lab report in the attached image into the JSON schema described in the system prompt. Return only the JSON object.`;
 
@@ -70,7 +72,8 @@ Extract every analyte reading you can identify. For each reading capture:
 - value: the numeric result as a number, OR null if the result is qualitative text. German reports use a decimal comma (e.g. "5,4") — emit it as 5.4.
 - valueText: the qualitative result text (e.g. "negativ", "positiv", "nicht nachweisbar"), OR null if the result is numeric.
 - unit: the measurement unit (e.g. "mg/dL", "%", "ng/mL"), or null if none is printed or the reading is qualitative.
-- referenceLow / referenceHigh: the reference-range bounds as numbers, or null. A one-sided range like "< 116" sets referenceHigh only; "> 40" sets referenceLow only.
+- referenceText: the reference range EXACTLY as printed beside the value, verbatim and complete, including its operator and unit if written (for example "3,5 - 5,0", "< 116", "bis 5,0", "150.000 - 400.000 /\u00b5l", "negativ"). Copy the characters; do NOT reformat, convert, or normalise them. Null only when no range is printed for that row.
+- referenceLow / referenceHigh: the SAME range reduced to numbers, when it reduces to numbers, else null. A one-sided range like "< 116" sets referenceHigh only; "> 40" sets referenceLow only.
 - takenAt: the per-row collection date in ISO 8601 (YYYY-MM-DD) if a date is printed for that row, else null.
 - confidence: an object { analyte, value, unit, range } with a 0..1 score for how confident you are in each field. Use a LOW score when the OCR text was garbled, ambiguous, or you had to guess — the text is lossy, so be conservative.
 
@@ -79,7 +82,7 @@ Set EXACTLY ONE of value / valueText per reading. Never invent a value you canno
 Also capture reportDate: the report's collection/sample date in ISO 8601 (YYYY-MM-DD), or null.
 
 Respond ONLY with a JSON object of this exact shape:
-{ "reportDate": string|null, "rows": [ { "analyte": string, "value": number|null, "valueText": string|null, "unit": string|null, "referenceLow": number|null, "referenceHigh": number|null, "takenAt": string|null, "confidence": { "analyte": number, "value": number, "unit": number, "range": number } } ] }`;
+{ "reportDate": string|null, "rows": [ { "analyte": string, "value": number|null, "valueText": string|null, "unit": string|null, "referenceText": string|null, "referenceLow": number|null, "referenceHigh": number|null, "takenAt": string|null, "confidence": { "analyte": number, "value": number, "unit": number, "range": number } } ] }`;
 
 /** A normalised ISO date string (YYYY-MM-DD) or null. */
 function normaliseDate(raw: string | null): string | null {
@@ -130,6 +133,7 @@ async function annotateRow(
 ): Promise<OcrExtractedRowDto> {
   const analyte = row.analyte.trim();
   const takenAt = normaliseDate(row.takenAt) ?? reportDate;
+  const printed = parseReferenceRange(row.referenceText, row.unit);
 
   // Biomarker match — case-insensitive on the catalog identity, presence-only.
   const existingBiomarker = await prisma.biomarker.findFirst({
@@ -175,8 +179,13 @@ async function annotateRow(
     value: row.value,
     valueText: row.valueText,
     unit: row.unit,
-    referenceLow: row.referenceLow,
-    referenceHigh: row.referenceHigh,
+    // Both readings of the printed window travel to the review screen: the
+    // derived bounds where the string yields them, and the string itself
+    // either way. A window the parser could not read is still the window the
+    // lab printed, so the user sees it and it reaches the row.
+    referenceLow: printed?.low ?? row.referenceLow,
+    referenceHigh: printed?.high ?? row.referenceHigh,
+    referenceText: printed?.text ?? null,
     takenAt,
     confidence: row.confidence,
     biomarkerMatch: existingBiomarker ? "existing" : "new",
diff --git a/src/lib/labs/parse-reference-range.ts b/src/lib/labs/parse-reference-range.ts
new file mode 100644
index 000000000..24e413f37
--- /dev/null
+++ b/src/lib/labs/parse-reference-range.ts
@@ -0,0 +1,207 @@
+/**
+ * Free-text reference-range parser for the range a lab report prints beside a
+ * value.
+ *
+ * A report states its window in prose, not in columns: "3,5 - 5,0", "< 5",
+ * "bis 5,0", "≥ 3,5", "150.000 - 400.000 /µl", or a word like "negativ" that
+ * carries no window at all. The document-reading path and the manual entry
+ * form both hand that string here.
+ *
+ * The contract is deliberately asymmetric:
+ *
+ *  - KEEPING the printed string is mandatory. `text` always carries what the
+ *    report said, whitespace-normalised and length-capped, whether or not a
+ *    bound could be derived from it. A window this parser cannot read is not
+ *    a window that gets thrown away.
+ *  - DERIVING bounds is best-effort and refuses on ambiguity. A string that
+ *    does not match one of the notations below yields `low: null, high: null`
+ *    beside the text. Absence reads as absence — the parser never picks a
+ *    plausible bound out of a string it did not understand, because a fake
+ *    window silently reclassifies a reading as normal or abnormal.
+ *
+ * Notations read (German and English, comma- or dot-decimal):
+ *
+ *   two-sided   3.5-5.0 · 3,5 – 5,0 · 3,5 bis 5,0 · 3.5 to 5.0 · 3,5 ... 5,0
+ *               von 3,5 bis 5,0 · [3,5 - 5,0] · (3.5-5.0)
+ *   upper only  < 5 · ≤ 5 · <= 5 · bis 5,0 · bis zu 5,0 · max. 5,0 ·
+ *               kleiner 5 · unter 5 · up to 5.0 · less than 5
+ *   lower only  > 3.5 · ≥ 3,5 · >= 3.5 · ab 3,5 · min. 3,5 · mindestens 3,5 ·
+ *               größer 3,5 · über 3,5 · at least 3.5
+ *
+ * Units are read, never converted. A window may carry the unit the report
+ * printed it in; when the caller states the reading's own unit and the two
+ * disagree, the bounds are refused and only the text survives. Converting
+ * mmol/L into mg/dL needs a per-analyte factor, so doing it here would be the
+ * parser deciding what the report meant.
+ */
+
+/** What a printed range yielded. `text` is set whenever the input was non-empty. */
+export interface ParsedReferenceRange {
+  /** Lower bound, or null when the notation states none / could not be read. */
+  low: number | null;
+  /** Upper bound, or null when the notation states none / could not be read. */
+  high: number | null;
+  /** The printed string, whitespace-normalised and capped. Never null here. */
+  text: string;
+}
+
+/**
+ * Storage cap for the verbatim string. A reference-range cell is a few
+ * characters; anything longer is a mis-segmented paragraph, and truncating it
+ * keeps a runaway transcription out of the column.
+ */
+export const SOURCE_REFERENCE_TEXT_MAX = 120;
+
+/** Magnitude ceiling. Beyond this a "bound" is a transcription artefact. */
+const MAX_ABS_BOUND = 1e12;
+
+/** One number token: optional sign, digits, any number of `.`/`,` groups. */
+const NUM = String.raw`[+-]?\d+(?:[.,]\d+)*`;
+
+/** Infix separators for a two-sided window. */
+const TWO_SIDED_SEP = String.raw`(?:-|–|—|‒|…|\.{2,3}|bis\s+zu|bis|to|until)`;
+
+/** Prefixes that state a ceiling only. */
+const UPPER_PREFIX = String.raw`(?:<=|<|≤|bis\s+zu|bis|max\.|maximal|max|kleiner\s+als|kleiner|unter|höchstens|hoechstens|up\s+to|less\s+than|below)`;
+
+/** Prefixes that state a floor only. */
+const LOWER_PREFIX = String.raw`(?:>=|>|≥|ab|mind\.|mindestens|minimal|min\.|min|größer\s+als|größer|groesser\s+als|groesser|über|ueber|at\s+least|greater\s+than|above)`;
+
+/**
+ * Trailing unit tail. Deliberately whitespace-free and comma-free: a real unit
+ * symbol ("mmol/l", "mg/dL", "%", "/µl", "10^9/L") never contains either, and
+ * refusing anything that does keeps a third number ("3,5 - 5,0 - 7,0") from
+ * being swallowed as if it were a unit.
+ */
+const UNIT_TAIL = String.raw`(?:\s*([^\s,]{1,24}))?`;
+
+const TWO_SIDED_RE = new RegExp(
+  `^(${NUM})\\s*${TWO_SIDED_SEP}\\s*(${NUM})${UNIT_TAIL}$`,
+  "iu",
+);
+const UPPER_RE = new RegExp(`^${UPPER_PREFIX}\\s*(${NUM})${UNIT_TAIL}$`, "iu");
+const LOWER_RE = new RegExp(`^${LOWER_PREFIX}\\s*(${NUM})${UNIT_TAIL}$`, "iu");
+
+/** Leading words that only introduce the window ("von 3,5 bis 5,0"). */
+const LEADING_FILLER_RE = /^(?:von|from|ref\.?|referenz|reference)\s+/iu;
+
+/**
+ * Read one number token into a JS number, or null when its separators are
+ * ambiguous.
+ *
+ * Separator rules, in order:
+ *   1. Both `.` and `,` present → the LAST one is the decimal mark, the other
+ *      groups thousands ("1.234,56" and "1,234.56" both read as 1234.56).
+ *   2. One separator kind, appearing more than once → all thousands
+ *      ("1.234.567").
+ *   3. One separator, appearing once, group ≠ 3 digits → decimal ("3,5").
+ *   4. One separator, appearing once, group = 3 digits → ambiguous in the
+ *      general case. Read as thousands only when the group is "000", which is
+ *      how a German report prints a rounded count ("150.000 - 400.000 /µl");
+ *      reading that as 150 would flag every normal platelet count as wildly
+ *      high. Any other 3-digit group ("1.234" — 1234 or 1.234?) is refused.
+ *
+ * The limit of rule 4 is real: a report that prints "5.000" meaning five with
+ * three decimal places is read as five thousand. The verbatim text is stored
+ * either way, so the printed window is never lost — only the derived bound is.
+ */
+function readNumber(token: string): number | null {
+  const sign = token.startsWith("-") ? -1 : 1;
+  const body = token.replace(/^[+-]/u, "");
+
+  const dots = (body.match(/\./gu) ?? []).length;
+  const commas = (body.match(/,/gu) ?? []).length;
+
+  let normalised: string;
+  if (dots > 0 && commas > 0) {
+    const decimalMark =
+      body.lastIndexOf(".") > body.lastIndexOf(",") ? "." : ",";
+    const grouping = decimalMark === "." ? "," : ".";
+    normalised = body.split(grouping).join("").replace(decimalMark, ".");
+  } else if (dots + commas === 0) {
+    normalised = body;
+  } else if (dots > 1 || commas > 1) {
+    normalised = body.replace(/[.,]/gu, "");
+  } else {
+    const idx = body.search(/[.,]/u);
+    const group = body.slice(idx + 1);
+    if (group.length !== 3) {
+      normalised = `${body.slice(0, idx)}.${group}`;
+    } else if (group === "000") {
+      normalised = body.slice(0, idx) + group;
+    } else {
+      return null;
+    }
+  }
+
+  const value = sign * Number(normalised);
+  if (!Number.isFinite(value) || Math.abs(value) > MAX_ABS_BOUND) return null;
+  return value;
+}
+
+/** Compare a printed unit against the reading's unit, ignoring case + spaces. */
+function unitsAgree(printed: string | undefined, reading: string | undefined) {
+  if (!printed) return true;
+  if (!reading || !reading.trim()) return true;
+  const norm = (u: string) => u.replace(/\s+/gu, "").toLowerCase();
+  return norm(printed) === norm(reading);
+}
+
+/**
+ * Parse the reference range a lab report printed for one reading.
+ *
+ * @param raw   the printed string, exactly as transcribed.
+ * @param unit  the reading's own unit, when known. A printed window in a
+ *              different unit yields text-only — never a converted bound.
+ * @returns null when there was nothing printed at all.
+ */
+export function parseReferenceRange(
+  raw: string | null | undefined,
+  unit?: string | null,
+): ParsedReferenceRange | null {
+  if (raw === null || raw === undefined) return null;
+  const text = raw
+    .replace(/\s+/gu, " ")
+    .trim()
+    .slice(0, SOURCE_REFERENCE_TEXT_MAX);
+  if (text === "") return null;
+
+  const noBounds: ParsedReferenceRange = { low: null, high: null, text };
+
+  // Strip a bracket wrapper and an introducing word for MATCHING only — the
+  // stored text stays exactly what the report printed.
+  let candidate = text;
+  const bracketed = /^[[(](.*)[\])]$/u.exec(candidate);
+  if (bracketed) candidate = bracketed[1].trim();
+  candidate = candidate.replace(LEADING_FILLER_RE, "").trim();
+
+  const two = TWO_SIDED_RE.exec(candidate);
+  if (two) {
+    if (!unitsAgree(two[3], unit ?? undefined)) return noBounds;
+    const low = readNumber(two[1]);
+    const high = readNumber(two[2]);
+    if (low === null || high === null) return noBounds;
+    // A transposed window is a transcription error, and swapping it would be a
+    // guess about which digit the lab meant. Refuse the bounds, keep the text.
+    if (low > high) return noBounds;
+    return { low, high, text };
+  }
+
+  const upper = UPPER_RE.exec(candidate);
+  if (upper) {
+    if (!unitsAgree(upper[2], unit ?? undefined)) return noBounds;
+    const high = readNumber(upper[1]);
+    return high === null ? noBounds : { low: null, high, text };
+  }
+
+  const lower = LOWER_RE.exec(candidate);
+  if (lower) {
+    if (!unitsAgree(lower[2], unit ?? undefined)) return noBounds;
+    const low = readNumber(lower[1]);
+    return low === null ? noBounds : { low, high: null, text };
+  }
+
+  // Anything else — "negativ", "siehe Befund", a bare number, prose — keeps its
+  // text and states no window.
+  return noBounds;
+}
diff --git a/src/lib/labs/reference-range.ts b/src/lib/labs/reference-range.ts
index 85369b176..8d7403091 100644
--- a/src/lib/labs/reference-range.ts
+++ b/src/lib/labs/reference-range.ts
@@ -61,3 +61,113 @@ export function formatReferenceRange(
   if (hasLow) return `≥ ${formatNumber(low as number)}`;
   return opts?.emptyText ?? "";
 }
+
+/**
+ * The reference range a lab report printed beside ONE reading, as stored on
+ * `LabResult.sourceReference*`.
+ */
+export interface SourceReferenceRange {
+  sourceReferenceLow: number | null;
+  sourceReferenceHigh: number | null;
+  sourceReferenceText: string | null;
+}
+
+/** Where the bounds a reading is judged against came from. */
+export type ReferenceRangeOrigin = "source" | "catalog" | "none";
+
+/** The bounds one reading is judged against, plus how they were arrived at. */
+export interface EffectiveReferenceRange {
+  /** The bound the verdict uses. */
+  low: number | null;
+  high: number | null;
+  origin: ReferenceRangeOrigin;
+  /** The catalog band, kept alongside so a surface can show both. */
+  catalogLow: number | null;
+  catalogHigh: number | null;
+  /** The printed window, kept verbatim. Null when the report stated none. */
+  sourceText: string | null;
+  /**
+   * True when the source window is in force AND the catalog states a window
+   * that differs from it. This is the case a reader must be told about: the
+   * same number reads differently against the two, so a surface that shows
+   * only one of them is showing a partial answer.
+   */
+  divergesFromCatalog: boolean;
+}
+
+/** Two bounds are the same window when both ends match (null included). */
+function sameWindow(
+  aLow: number | null,
+  aHigh: number | null,
+  bLow: number | null,
+  bHigh: number | null,
+): boolean {
+  return aLow === bLow && aHigh === bHigh;
+}
+
+/**
+ * Resolve the reference window ONE reading is judged against.
+ *
+ * A lab runs its own method on its own device, and the physician reads the
+ * value against the window printed on that report. So for a reading that
+ * carries a source window, the source window wins — for that reading alone.
+ * The catalog band stays the net for every reading that carries none.
+ *
+ * A source window counts as stating a window only when it yields at least one
+ * numeric bound. A printed string with no derivable bound ("negativ", "siehe
+ * Befund") is carried through as `sourceText` but never displaces the catalog:
+ * a range that could not be read is not an argument for having no range.
+ *
+ * This function is the ONLY place that precedence is expressed. Every surface
+ * that classifies a reading — the API DTO, the doctor report, insights, the
+ * coach snapshot, the MCP read, the FHIR export — routes through it, so a
+ * reading cannot read as in-range on one surface and out on another.
+ */
+export function resolveEffectiveReferenceRange(
+  catalogLow: number | null | undefined,
+  catalogHigh: number | null | undefined,
+  source: SourceReferenceRange | null | undefined,
+): EffectiveReferenceRange {
+  const cLow = catalogLow ?? null;
+  const cHigh = catalogHigh ?? null;
+  const sLow = source?.sourceReferenceLow ?? null;
+  const sHigh = source?.sourceReferenceHigh ?? null;
+  const sourceText = source?.sourceReferenceText ?? null;
+
+  if (sLow !== null || sHigh !== null) {
+    return {
+      low: sLow,
+      high: sHigh,
+      origin: "source",
+      catalogLow: cLow,
+      catalogHigh: cHigh,
+      sourceText,
+      divergesFromCatalog:
+        (cLow !== null || cHigh !== null) &&
+        !sameWindow(sLow, sHigh, cLow, cHigh),
+    };
+  }
+
+  return {
+    low: cLow,
+    high: cHigh,
+    origin: cLow !== null || cHigh !== null ? "catalog" : "none",
+    catalogLow: cLow,
+    catalogHigh: cHigh,
+    sourceText,
+    divergesFromCatalog: false,
+  };
+}
+
+/**
+ * Classify one reading against its effective window. Qualitative readings
+ * (no numeric value) always report `"unknown"` — there is nothing to compare
+ * against bounds, and a fabricated verdict is worse than none.
+ */
+export function classifyAgainstEffectiveRange(
+  value: number | null,
+  effective: EffectiveReferenceRange,
+): ReferenceRangeStatus {
+  if (value === null) return "unknown";
+  return classifyReferenceRange(value, effective.low, effective.high);
+}
diff --git a/src/lib/labs/serialise.ts b/src/lib/labs/serialise.ts
index adbe528dc..2dc6f6ced 100644
--- a/src/lib/labs/serialise.ts
+++ b/src/lib/labs/serialise.ts
@@ -10,13 +10,40 @@
  *  - If the row is unlinked (legacy / pre-backfill), it falls back to its own
  *    free-text `analyte` / `unit` / `reference*` columns.
  *
- * Either way the verdict (`rangeStatus`) is computed from the RESOLVED bounds
- * via `classifyReferenceRange`. The DTO carries the resolved values so the web
- * client AND the iOS client render the same numbers — neither recomputes the
- * range or guesses the unit. This is the server-authoritative-parity rule for
- * Labs.
+ * On top of that the reading's OWN printed window wins. A lab report states
+ * the range its method and device produce right beside the value, and that is
+ * the window a physician evaluates against; the catalog band is the net for
+ * readings that carry none. `resolveEffectiveReferenceRange` owns that
+ * precedence and this file is one of its callers, not a second copy of it.
+ *
+ * The DTO therefore carries three windows and says which one is in force:
+ *
+ *  - `referenceLow` / `referenceHigh` — the EFFECTIVE bounds, the ones
+ *    `rangeStatus` was computed from. A client that reads only these fields
+ *    (including an iOS build that predates the source window) renders the
+ *    right numbers and the right verdict with no change of its own.
+ *  - `catalogReferenceLow` / `catalogReferenceHigh` — the catalog band, so a
+ *    surface can paint both and show where they part.
+ *  - `sourceReferenceLow` / `sourceReferenceHigh` / `sourceReferenceText` —
+ *    what the report printed, the last verbatim.
+ *
+ * `referenceOrigin` names which window is in force and
+ * `referenceDivergesFromCatalog` flags the case a reader must be told about.
+ * Every value is resolved server-side; neither client recomputes a range,
+ * guesses a unit, or re-derives the verdict.
+ *
+ * The two serialisers below spell every field out rather than spreading a
+ * shared helper: `written-outcome-response-consumer-guard` walks these object
+ * literals to enumerate the response leaves and pair each with a client
+ * reader, and a spread of a function call hides them from it. A field added
+ * here must be visible there.
  */
-import { classifyReferenceRange } from "@/lib/labs/reference-range";
+import {
+  classifyAgainstEffectiveRange,
+  resolveEffectiveReferenceRange,
+  type EffectiveReferenceRange,
+  type ReferenceRangeOrigin,
+} from "@/lib/labs/reference-range";
 
 /** The minimal biomarker shape the resolver needs (no encrypted context). */
 export interface ResolvedBiomarker {
@@ -40,6 +67,10 @@ export interface LabRow {
   unit: string;
   referenceLow: number | null;
   referenceHigh: number | null;
+  /** The window the source report printed for THIS reading. */
+  sourceReferenceLow: number | null;
+  sourceReferenceHigh: number | null;
+  sourceReferenceText: string | null;
   takenAt: Date;
   source: string;
   biomarkerId: string | null;
@@ -48,60 +79,95 @@ export interface LabRow {
   updatedAt: Date;
 }
 
-/**
- * Resolve the canonical name / unit / bounds / panel for a lab row, preferring
- * the linked biomarker over the legacy per-row fields. Returns a plain shape
- * the list + detail serialisers both build on.
- */
-export function resolveLabFields(
-  row: Pick<
-    LabRow,
-    | "analyte"
-    | "unit"
-    | "referenceLow"
-    | "referenceHigh"
-    | "panel"
-    | "biomarkerId"
-  >,
-  biomarker: ResolvedBiomarker | null | undefined,
-): {
+/** The columns `resolveLabFields` needs off a lab row. */
+export type LabFieldRow = Pick<
+  LabRow,
+  | "analyte"
+  | "unit"
+  | "referenceLow"
+  | "referenceHigh"
+  | "sourceReferenceLow"
+  | "sourceReferenceHigh"
+  | "sourceReferenceText"
+  | "panel"
+  | "biomarkerId"
+>;
+
+/** What every lab surface reads off a row: identity, unit, and one window. */
+export interface ResolvedLabFields {
   analyte: string;
   unit: string;
+  panel: string | null;
+  /** The bounds in force for this reading — source window first, catalog next. */
   referenceLow: number | null;
   referenceHigh: number | null;
-  panel: string | null;
-} {
-  if (biomarker) {
-    return {
-      analyte: biomarker.name,
-      unit: biomarker.unit,
-      referenceLow: biomarker.lowerBound,
-      referenceHigh: biomarker.upperBound,
-      panel: biomarker.panel,
-    };
-  }
-  return {
-    analyte: row.analyte,
-    unit: row.unit,
-    referenceLow: row.referenceLow,
-    referenceHigh: row.referenceHigh,
-    panel: row.panel,
-  };
+  /** The catalog band, so a surface can show both windows. */
+  catalogReferenceLow: number | null;
+  catalogReferenceHigh: number | null;
+  /** What the source report printed for this reading. */
+  sourceReferenceLow: number | null;
+  sourceReferenceHigh: number | null;
+  sourceReferenceText: string | null;
+  referenceOrigin: ReferenceRangeOrigin;
+  referenceDivergesFromCatalog: boolean;
+  /** The resolved window as one value, for callers that pass it on. */
+  effectiveRange: EffectiveReferenceRange;
 }
 
 /**
- * v1.18.9 — the reference-range verdict for a row. A qualitative row (no
- * numeric `value`) has nothing to compare against the bounds, so it always
- * reports `"unknown"` — the neutral, no-verdict state — never a fabricated
- * in/out classification. A numeric row classifies against the resolved bounds.
+ * Resolve the canonical name / unit / window / panel for a lab row.
+ *
+ * Two resolutions happen here, in this order:
+ *
+ *  1. Identity + catalog band: the linked biomarker wins over the row's legacy
+ *     free-text columns (an unlinked pre-backfill row falls back to its own).
+ *  2. The window in force: the reading's printed source range wins over the
+ *     catalog band, through `resolveEffectiveReferenceRange`.
+ *
+ * Every lab surface calls this, so the window a reading is judged against is
+ * the same on the API, the doctor report, insights, the coach, MCP and FHIR.
  */
-function rowRangeStatus(
-  value: number | null,
-  referenceLow: number | null,
-  referenceHigh: number | null,
-) {
-  if (value === null) return "unknown" as const;
-  return classifyReferenceRange(value, referenceLow, referenceHigh);
+export function resolveLabFields(
+  row: LabFieldRow,
+  biomarker: ResolvedBiomarker | null | undefined,
+): ResolvedLabFields {
+  const identity = biomarker
+    ? {
+        analyte: biomarker.name,
+        unit: biomarker.unit,
+        panel: biomarker.panel,
+        catalogLow: biomarker.lowerBound,
+        catalogHigh: biomarker.upperBound,
+      }
+    : {
+        analyte: row.analyte,
+        unit: row.unit,
+        panel: row.panel,
+        catalogLow: row.referenceLow,
+        catalogHigh: row.referenceHigh,
+      };
+
+  const effectiveRange = resolveEffectiveReferenceRange(
+    identity.catalogLow,
+    identity.catalogHigh,
+    row,
+  );
+
+  return {
+    analyte: identity.analyte,
+    unit: identity.unit,
+    panel: identity.panel,
+    referenceLow: effectiveRange.low,
+    referenceHigh: effectiveRange.high,
+    catalogReferenceLow: effectiveRange.catalogLow,
+    catalogReferenceHigh: effectiveRange.catalogHigh,
+    sourceReferenceLow: row.sourceReferenceLow,
+    sourceReferenceHigh: row.sourceReferenceHigh,
+    sourceReferenceText: effectiveRange.sourceText,
+    referenceOrigin: effectiveRange.origin,
+    referenceDivergesFromCatalog: effectiveRange.divergesFromCatalog,
+    effectiveRange,
+  };
 }
 
 /**
@@ -123,13 +189,21 @@ export function serialiseLabResult(
     unit: resolved.unit,
     referenceLow: resolved.referenceLow,
     referenceHigh: resolved.referenceHigh,
+    catalogReferenceLow: resolved.catalogReferenceLow,
+    catalogReferenceHigh: resolved.catalogReferenceHigh,
+    sourceReferenceLow: resolved.sourceReferenceLow,
+    sourceReferenceHigh: resolved.sourceReferenceHigh,
+    sourceReferenceText: resolved.sourceReferenceText,
+    referenceOrigin: resolved.referenceOrigin,
+    referenceDivergesFromCatalog: resolved.referenceDivergesFromCatalog,
     takenAt: row.takenAt.toISOString(),
     source: row.source,
     hasNote: row.noteEncrypted !== null,
-    rangeStatus: rowRangeStatus(
+    // A qualitative row has no number to place against bounds, so it reports
+    // the neutral "unknown" rather than a fabricated in/out verdict.
+    rangeStatus: classifyAgainstEffectiveRange(
       row.value,
-      resolved.referenceLow,
-      resolved.referenceHigh,
+      resolved.effectiveRange,
     ),
     createdAt: row.createdAt.toISOString(),
     updatedAt: row.updatedAt.toISOString(),
@@ -156,13 +230,19 @@ export function serialiseLabResultDetail(
     unit: resolved.unit,
     referenceLow: resolved.referenceLow,
     referenceHigh: resolved.referenceHigh,
+    catalogReferenceLow: resolved.catalogReferenceLow,
+    catalogReferenceHigh: resolved.catalogReferenceHigh,
+    sourceReferenceLow: resolved.sourceReferenceLow,
+    sourceReferenceHigh: resolved.sourceReferenceHigh,
+    sourceReferenceText: resolved.sourceReferenceText,
+    referenceOrigin: resolved.referenceOrigin,
+    referenceDivergesFromCatalog: resolved.referenceDivergesFromCatalog,
     takenAt: row.takenAt.toISOString(),
     source: row.source,
     note,
-    rangeStatus: rowRangeStatus(
+    rangeStatus: classifyAgainstEffectiveRange(
       row.value,
-      resolved.referenceLow,
-      resolved.referenceHigh,
+      resolved.effectiveRange,
     ),
     createdAt: row.createdAt.toISOString(),
     updatedAt: row.updatedAt.toISOString(),
diff --git a/src/lib/mcp/rich-reads.ts b/src/lib/mcp/rich-reads.ts
index 14d22261f..e670c7d24 100644
--- a/src/lib/mcp/rich-reads.ts
+++ b/src/lib/mcp/rich-reads.ts
@@ -48,7 +48,7 @@ import {
   type MetricStatusMetricId,
 } from "@/lib/insights/metric-status-registry";
 import { allSignals, getSignal } from "@/lib/signals/registry";
-import { classifyReferenceRange } from "@/lib/labs/reference-range";
+import { classifyAgainstEffectiveRange } from "@/lib/labs/reference-range";
 import { resolveLabFields } from "@/lib/labs/serialise";
 import { sanitizeValueText } from "@/lib/ai/coach/labs-snapshot";
 import { encodeOffsetCursor } from "@/lib/mcp/pagination";
@@ -1316,6 +1316,9 @@ export async function getLabHistory(
       unit: true,
       referenceLow: true,
       referenceHigh: true,
+      sourceReferenceLow: true,
+      sourceReferenceHigh: true,
+      sourceReferenceText: true,
       takenAt: true,
       biomarkerId: true,
       biomarker: {
@@ -1350,14 +1353,10 @@ export async function getLabHistory(
       unit: resolved.unit,
       referenceLow: resolved.referenceLow,
       referenceHigh: resolved.referenceHigh,
-      rangeStatus:
-        row.value === null
-          ? "unknown"
-          : classifyReferenceRange(
-              row.value,
-              resolved.referenceLow,
-              resolved.referenceHigh,
-            ),
+      rangeStatus: classifyAgainstEffectiveRange(
+        row.value,
+        resolved.effectiveRange,
+      ),
       takenAt: row.takenAt.toISOString(),
     };
   });
diff --git a/src/lib/measurements/__tests__/plausibility-gate.test.ts b/src/lib/measurements/__tests__/plausibility-gate.test.ts
new file mode 100644
index 000000000..074d32600
--- /dev/null
+++ b/src/lib/measurements/__tests__/plausibility-gate.test.ts
@@ -0,0 +1,222 @@
+/**
+ * The ingest-side plausibility gate.
+ *
+ * `VALUE_RANGES` is the band the application declares a metric can occupy, and
+ * every path a person can drive has always enforced it. The provider sync
+ * writers did not, which is how a row the application itself calls impossible
+ * reached the table and poisoned every mean and personal band derived from it.
+ * These cases pin the two halves of the fix: the refusal, and the fact that a
+ * refusal is never silent.
+ */
+import { beforeEach, describe, expect, it } from "vitest";
+
+import { WideEventBuilder } from "@/lib/logging/event-builder";
+import { eventStorage } from "@/lib/logging/context";
+import {
+  RANGE_REJECTED_META_KEY,
+  classifyRangeRejection,
+  dropImplausibleMeasurements,
+  recordRangeRejections,
+  type RangeRejectionTally,
+} from "../plausibility-gate";
+
+let event: WideEventBuilder;
+
+function withEvent<T>(run: () => T): T {
+  return eventStorage.run(event, run);
+}
+
+function tally(): RangeRejectionTally | undefined {
+  return event.toJSON().meta?.[RANGE_REJECTED_META_KEY] as
+    RangeRejectionTally | undefined;
+}
+
+beforeEach(() => {
+  event = new WideEventBuilder("background");
+});
+
+describe("classifyRangeRejection", () => {
+  it("passes a value inside the metric's declared band", () => {
+    // PULSE is declared 20–300; both edges are inclusive.
+    expect(classifyRangeRejection("PULSE", 60)).toBeNull();
+    expect(classifyRangeRejection("PULSE", 20)).toBeNull();
+    expect(classifyRangeRejection("PULSE", 300)).toBeNull();
+  });
+
+  it("names the edge an out-of-band value broke", () => {
+    expect(classifyRangeRejection("PULSE", 55643821.505)).toEqual({
+      type: "PULSE",
+      direction: "above_max",
+    });
+    expect(classifyRangeRejection("PULSE", 19)).toEqual({
+      type: "PULSE",
+      direction: "below_min",
+    });
+  });
+
+  it("refuses a non-finite value whatever the metric", () => {
+    expect(classifyRangeRejection("PULSE", Number.NaN)).toEqual({
+      type: "PULSE",
+      direction: "not_finite",
+    });
+    // No declared band, so the value itself is the only thing to judge.
+    expect(
+      classifyRangeRejection("NOT_A_METRIC", Number.POSITIVE_INFINITY),
+    ).toEqual({ type: "NOT_A_METRIC", direction: "not_finite" });
+  });
+
+  it("passes a metric with no declared band — an absent range is an absent fact", () => {
+    expect(classifyRangeRejection("NOT_A_METRIC", 9_999_999)).toBeNull();
+  });
+});
+
+describe("dropImplausibleMeasurements", () => {
+  it("keeps the in-band rows and returns them untouched", () => {
+    const rows = [
+      { type: "PULSE", value: 60 },
+      { type: "WEIGHT", value: 82.4 },
+    ];
+    const kept = withEvent(() =>
+      dropImplausibleMeasurements("withings", rows, (r) => r),
+    );
+
+    expect(kept).toEqual(rows);
+    expect(kept[0]).toBe(rows[0]);
+    // Nothing was refused, so the event carries no tally at all — absence
+    // reads as absence.
+    expect(tally()).toBeUndefined();
+    expect(event.toJSON().warnings).toBeUndefined();
+  });
+
+  it("drops the out-of-band rows and tallies them on the wide event", () => {
+    const kept = withEvent(() =>
+      dropImplausibleMeasurements(
+        "withings",
+        [
+          { type: "PULSE", value: 60 },
+          { type: "PULSE", value: 55643821.505 },
+          { type: "PULSE", value: 900 },
+          { type: "WEIGHT", value: 0.2 },
+        ],
+        (r) => r,
+      ),
+    );
+
+    expect(kept).toEqual([{ type: "PULSE", value: 60 }]);
+
+    const recorded = tally();
+    expect(recorded).toEqual({
+      total: 3,
+      buckets: [
+        {
+          source: "withings",
+          type: "PULSE",
+          direction: "above_max",
+          count: 2,
+        },
+        {
+          source: "withings",
+          type: "WEIGHT",
+          direction: "below_min",
+          count: 1,
+        },
+      ],
+    });
+  });
+
+  it("keeps the refused readings out of the log line", () => {
+    withEvent(() =>
+      dropImplausibleMeasurements(
+        "withings",
+        [{ type: "PULSE", value: 55643821.505 }],
+        (r) => r,
+      ),
+    );
+
+    // The value is a health reading. The tally says which metric, which
+    // provider and which edge — never the number itself.
+    const serialised = JSON.stringify(event.toJSON());
+    expect(serialised).not.toContain("55643821");
+  });
+
+  it("lifts the event to warn once per provider", () => {
+    withEvent(() => {
+      dropImplausibleMeasurements(
+        "withings",
+        [{ type: "PULSE", value: 900 }],
+        (r) => r,
+      );
+      dropImplausibleMeasurements(
+        "withings",
+        [{ type: "PULSE", value: 901 }],
+        (r) => r,
+      );
+      dropImplausibleMeasurements(
+        "fitbit",
+        [{ type: "PULSE", value: 902 }],
+        (r) => r,
+      );
+    });
+
+    expect(event.getLevel()).toBe("warn");
+    expect(event.toJSON().warnings).toHaveLength(2);
+    expect(event.toJSON().warnings?.[0]).toContain("withings");
+    expect(event.toJSON().warnings?.[1]).toContain("fitbit");
+  });
+
+  it("accumulates across calls instead of overwriting the previous tally", () => {
+    // Fitbit gates once per resource leg, and the reconciler gates once per
+    // row: a tally that replaced rather than merged would report only the
+    // last batch, and a run that dropped hundreds would read as dropping one.
+    withEvent(() => {
+      dropImplausibleMeasurements(
+        "fitbit",
+        [{ type: "PULSE", value: 900 }],
+        (r) => r,
+      );
+      dropImplausibleMeasurements(
+        "fitbit",
+        [
+          { type: "PULSE", value: 901 },
+          { type: "OXYGEN_SATURATION", value: 4 },
+        ],
+        (r) => r,
+      );
+    });
+
+    expect(tally()).toEqual({
+      total: 3,
+      buckets: [
+        {
+          source: "fitbit",
+          type: "OXYGEN_SATURATION",
+          direction: "below_min",
+          count: 1,
+        },
+        { source: "fitbit", type: "PULSE", direction: "above_max", count: 2 },
+      ],
+    });
+  });
+
+  it("still drops outside a wide-event context", () => {
+    // A sync running without an ambient event has nowhere to report. The row
+    // is refused anyway: observability is what is lost, never the guarantee.
+    const kept = dropImplausibleMeasurements(
+      "nightscout",
+      [
+        { type: "BLOOD_GLUCOSE", value: 110 },
+        { type: "BLOOD_GLUCOSE", value: 9_000 },
+      ],
+      (r) => r,
+    );
+    expect(kept).toEqual([{ type: "BLOOD_GLUCOSE", value: 110 }]);
+  });
+});
+
+describe("recordRangeRejections", () => {
+  it("writes nothing when there is nothing to report", () => {
+    withEvent(() => recordRangeRejections("withings", []));
+    expect(tally()).toBeUndefined();
+    expect(event.getLevel()).toBe("info");
+  });
+});
diff --git a/src/lib/measurements/__tests__/reconcile-external-measurement.test.ts b/src/lib/measurements/__tests__/reconcile-external-measurement.test.ts
index 5a2d012fd..9fa5c3cf7 100644
--- a/src/lib/measurements/__tests__/reconcile-external-measurement.test.ts
+++ b/src/lib/measurements/__tests__/reconcile-external-measurement.test.ts
@@ -1,6 +1,9 @@
 import { describe, expect, it, vi } from "vitest";
 
 import type { Prisma } from "@/generated/prisma/client";
+import { eventStorage } from "@/lib/logging/context";
+import { WideEventBuilder } from "@/lib/logging/event-builder";
+import { RANGE_REJECTED_META_KEY } from "../plausibility-gate";
 import {
   reconcileExternalMeasurement,
   type ExternalMeasurementWrite,
@@ -383,3 +386,104 @@ describe("reconcileExternalMeasurement", () => {
     );
   });
 });
+
+/**
+ * The reconciler is the shared write seam for every provider that does not
+ * hold Prisma itself — Polar, Oura, WHOOP, the Withings sleep leg, the Apple
+ * export importer, the batch endpoint. Gating here rather than at each caller
+ * is what makes a provider added tomorrow inherit the refusal instead of
+ * having to remember a check it never knew about.
+ */
+describe("reconcileExternalMeasurement — plausibility gate", () => {
+  it("reconciles a value inside the metric's declared band", async () => {
+    const { tx, measurement } = transaction([]);
+    measurement.create.mockResolvedValue(row({ id: "fresh" }));
+
+    // PULSE is declared 20–300.
+    const verdict = await reconcileExternalMeasurement(
+      tx,
+      desired({ type: "PULSE", value: 112, unit: "bpm", sleepStage: null }),
+    );
+
+    expect(verdict.status).toBe("inserted");
+    expect(measurement.create).toHaveBeenCalledTimes(1);
+  });
+
+  it("refuses an out-of-band value without touching the transaction", async () => {
+    const { tx, measurement } = transaction([]);
+
+    const verdict = await reconcileExternalMeasurement(
+      tx,
+      desired({
+        type: "PULSE",
+        value: 55643821.505,
+        unit: "bpm",
+        sleepStage: null,
+      }),
+    );
+
+    expect(verdict).toEqual({
+      status: "rejected_range",
+      rejection: { type: "PULSE", direction: "above_max" },
+    });
+    // No row written, no row updated, and no savepoint opened — the refusal
+    // happens before the reconciler does any work at all.
+    expect(measurement.create).not.toHaveBeenCalled();
+    expect(measurement.update).not.toHaveBeenCalled();
+    expect(tx.$executeRawUnsafe).not.toHaveBeenCalled();
+  });
+
+  it("refuses rather than overwriting a good stored row", async () => {
+    // The dangerous shape: a live row already holds a real reading, and the
+    // provider re-sends the same identity carrying an impossible value. The
+    // update branch would have rewritten a good value with a bad one.
+    const existing = row({
+      id: "exact-row",
+      type: "PULSE",
+      value: 62,
+      unit: "bpm",
+      sleepStage: null,
+      measuredAt: new Date("2026-07-20T06:30:00.000Z"),
+    });
+    const { tx, measurement } = transaction([existing]);
+
+    const verdict = await reconcileExternalMeasurement(
+      tx,
+      desired({
+        type: "PULSE",
+        value: 55643821.505,
+        unit: "bpm",
+        sleepStage: null,
+      }),
+    );
+
+    expect(verdict.status).toBe("rejected_range");
+    expect(measurement.update).not.toHaveBeenCalled();
+  });
+
+  it("tallies the refusal on the ambient wide event under the provider", async () => {
+    const { tx } = transaction([]);
+    const event = new WideEventBuilder("background");
+
+    await eventStorage.run(event, () =>
+      reconcileExternalMeasurement(
+        tx,
+        desired({
+          type: "PULSE",
+          value: 55643821.505,
+          unit: "bpm",
+          source: "WHOOP",
+          sleepStage: null,
+        }),
+      ),
+    );
+
+    expect(event.toJSON().meta?.[RANGE_REJECTED_META_KEY]).toEqual({
+      total: 1,
+      buckets: [
+        { source: "whoop", type: "PULSE", direction: "above_max", count: 1 },
+      ],
+    });
+    expect(event.getLevel()).toBe("warn");
+  });
+});
diff --git a/src/lib/measurements/import-apple-health-export.ts b/src/lib/measurements/import-apple-health-export.ts
index fc1e9f838..31d0b7dc2 100644
--- a/src/lib/measurements/import-apple-health-export.ts
+++ b/src/lib/measurements/import-apple-health-export.ts
@@ -720,6 +720,16 @@ export async function streamParseExportXml(
           ),
         );
 
+        // The reconciler carries the same plausibility gate the block above
+        // already applied, so this arm means the two disagreed. Tally it under
+        // the same counter the earlier guard uses and count no row.
+        if (verdict.status === "rejected_range") {
+          unknown[`${type}::aggregate_out_of_range`] =
+            (unknown[`${type}::aggregate_out_of_range`] ?? 0) + 1;
+          stat.durationMs += Date.now() - rowStart;
+          continue;
+        }
+
         cumulativeEstimatedDays.add(dayKey);
         cumulativeEstimatedRows += 1;
         if (verdict.status === "inserted") {
diff --git a/src/lib/measurements/plausibility-gate.ts b/src/lib/measurements/plausibility-gate.ts
new file mode 100644
index 000000000..d079f5391
--- /dev/null
+++ b/src/lib/measurements/plausibility-gate.ts
@@ -0,0 +1,192 @@
+/**
+ * The ingest-side half of the app's plausibility domain.
+ *
+ * `VALUE_RANGES` in `@/lib/validations/measurement` is the band the
+ * application declares a metric can occupy — PULSE 20–300, WEIGHT 1–500,
+ * SLEEP_DURATION 0–1440 minutes. Every path a person can drive enforces it:
+ * the measurement routes, the batch endpoint, the CSV and Apple-export
+ * importers, MCP, Telegram. The provider sync writers did not. They took the
+ * number the remote handed over and wrote it, so a decode slip or a glitched
+ * device landed a row the application itself calls impossible, and every mean,
+ * median and personal band downstream digested it as a reading.
+ *
+ * `isPlausibleMetricValue` (in `value-domain.ts`) already answers the question
+ * for the READ side, which is where the damage surfaced first. This module is
+ * the same question asked one layer earlier, at the point of writing, so the
+ * row never lands. The two ends share the one predicate on purpose: a band the
+ * reader hides but the writer accepts is a row that exists and cannot be seen,
+ * which is the worse of the two failures.
+ *
+ * ## Disposition: drop, and say so
+ *
+ * An out-of-band incoming value is DROPPED. Not clamped (a clamp invents a
+ * reading nobody took), not stored-and-flagged (a quarantined row is still a
+ * row, and every consumer would need to learn the flag), not fatal to the
+ * batch (one glitched sample must not strand the sync's other readings behind
+ * a held watermark). Absence reads as absence: the sample is simply not part
+ * of the record.
+ *
+ * A silent drop, though, is indistinguishable from a provider that sent
+ * nothing — so every drop is tallied onto the ambient wide event under
+ * {@link RANGE_REJECTED_META_KEY}, with the metric type, the provider, and the
+ * direction it broke the band in. Counts only. The value itself is a health
+ * reading and never enters the log line; the direction plus the metric's own
+ * declared bound is what a diagnosis actually needs.
+ *
+ * ## Why meta and not `action`
+ *
+ * A wide event holds exactly ONE action, and `setAction` replaces it. A drop
+ * happens in the middle of a sync whose action is decided at the end, so an
+ * `action` set here is either clobbered a moment later (the drop vanishes) or,
+ * on the paths that annotate no terminal action, relabels an otherwise
+ * successful sync as a rejection. Meta accumulates, survives every later
+ * `setAction`, and is the shape a dashboard can sum. One warning per provider
+ * per event rides along so the drop also lifts the event's level to `warn`
+ * rather than hiding inside a green line.
+ */
+import { annotate, getEvent } from "@/lib/logging/context";
+import { isPlausibleMetricValue } from "@/lib/measurements/value-domain";
+import { VALUE_RANGES } from "@/lib/validations/measurement";
+
+/**
+ * Stable meta key the tally lands under. Pinned so dashboards can count it
+ * across providers without knowing which one wrote the event.
+ */
+export const RANGE_REJECTED_META_KEY = "measurement.range_rejected";
+
+/** Which edge of the declared band the value broke, or that it was not a number. */
+export type RangeRejectionDirection = "below_min" | "above_max" | "not_finite";
+
+/** One refused reading, reduced to the facts that carry no health value. */
+export interface MeasurementRangeRejection {
+  /** `MeasurementType` of the refused reading. */
+  type: string;
+  direction: RangeRejectionDirection;
+}
+
+/** One (provider, metric, direction) cell of the event's running tally. */
+export interface RangeRejectionBucket {
+  source: string;
+  type: string;
+  direction: RangeRejectionDirection;
+  count: number;
+}
+
+/** The pinned meta shape written under {@link RANGE_REJECTED_META_KEY}. */
+export interface RangeRejectionTally {
+  total: number;
+  buckets: RangeRejectionBucket[];
+}
+
+/**
+ * Classify a candidate write against the metric's declared band.
+ *
+ * Returns `null` when the value may be written. A type with no declared range
+ * passes — an absent range is an absent fact, never a guessed one, and the
+ * same asymmetry the read side uses (`isPlausibleMetricValue`). A non-finite
+ * value never passes, whatever the type: NaN is not an input to anything.
+ */
+export function classifyRangeRejection(
+  type: string,
+  value: number,
+): MeasurementRangeRejection | null {
+  if (isPlausibleMetricValue(type, value)) return null;
+  if (!Number.isFinite(value)) return { type, direction: "not_finite" };
+  const range = VALUE_RANGES[type];
+  // `isPlausibleMetricValue` only answers false for a finite value when the
+  // type HAS a range, so the lookup cannot miss here.
+  return {
+    type,
+    direction: value < range!.min ? "below_min" : "above_max",
+  };
+}
+
+function readTally(): RangeRejectionTally {
+  const existing = getEvent()?.toJSON().meta?.[RANGE_REJECTED_META_KEY];
+  if (
+    existing !== null &&
+    typeof existing === "object" &&
+    Array.isArray((existing as RangeRejectionTally).buckets)
+  ) {
+    return existing as RangeRejectionTally;
+  }
+  return { total: 0, buckets: [] };
+}
+
+/**
+ * Fold refusals onto the ambient wide event.
+ *
+ * Merges with whatever the event already carries, so a provider that gates
+ * several batches (or reconciles row by row) accumulates instead of
+ * overwriting. Outside a wide-event context this is a no-op — the caller still
+ * drops the row, it simply has nowhere to report.
+ */
+export function recordRangeRejections(
+  source: string,
+  rejections: readonly MeasurementRangeRejection[],
+): void {
+  if (rejections.length === 0) return;
+  const evt = getEvent();
+  if (!evt) return;
+
+  const tally = readTally();
+  const firstForSource = !tally.buckets.some((b) => b.source === source);
+
+  for (const rejection of rejections) {
+    const bucket = tally.buckets.find(
+      (b) =>
+        b.source === source &&
+        b.type === rejection.type &&
+        b.direction === rejection.direction,
+    );
+    if (bucket) bucket.count += 1;
+    else
+      tally.buckets.push({
+        source,
+        type: rejection.type,
+        direction: rejection.direction,
+        count: 1,
+      });
+    tally.total += 1;
+  }
+
+  tally.buckets.sort(
+    (a, b) =>
+      a.source.localeCompare(b.source) ||
+      a.type.localeCompare(b.type) ||
+      a.direction.localeCompare(b.direction),
+  );
+
+  annotate({ meta: { [RANGE_REJECTED_META_KEY]: tally } });
+  if (firstForSource) {
+    evt.addWarning(
+      `${source}: refused reading(s) outside the declared plausibility range — ` +
+        `dropped, see meta.${RANGE_REJECTED_META_KEY}`,
+    );
+  }
+}
+
+/**
+ * Keep the rows whose value sits inside the metric's declared band; tally and
+ * drop the rest.
+ *
+ * `select` exists because the sync writers carry their own row shapes and none
+ * of them is worth reshaping at the call site: the gate reads the two fields
+ * it needs and returns the caller's own objects untouched.
+ */
+export function dropImplausibleMeasurements<T>(
+  source: string,
+  rows: readonly T[],
+  select: (row: T) => { type: string; value: number },
+): T[] {
+  const kept: T[] = [];
+  const rejections: MeasurementRangeRejection[] = [];
+  for (const row of rows) {
+    const { type, value } = select(row);
+    const rejection = classifyRangeRejection(type, value);
+    if (rejection) rejections.push(rejection);
+    else kept.push(row);
+  }
+  recordRangeRejections(source, rejections);
+  return kept;
+}
diff --git a/src/lib/measurements/reconcile-external-measurement.ts b/src/lib/measurements/reconcile-external-measurement.ts
index 031dda441..d4fb50784 100644
--- a/src/lib/measurements/reconcile-external-measurement.ts
+++ b/src/lib/measurements/reconcile-external-measurement.ts
@@ -4,6 +4,11 @@ import {
   type MeasurementAggregationProvenance,
   type Prisma as PrismaTypes,
 } from "@/generated/prisma/client";
+import {
+  classifyRangeRejection,
+  recordRangeRejections,
+  type MeasurementRangeRejection,
+} from "@/lib/measurements/plausibility-gate";
 
 const SAVEPOINT = "measurement_identity_reconcile";
 
@@ -50,6 +55,18 @@ export type MeasurementReconciliationVerdict =
   | {
       status: "failed";
       error: { message: string; code?: string };
+    }
+  | {
+      /**
+       * The incoming value sits outside the metric's declared plausibility
+       * band, so nothing was written and no existing row was touched. Not a
+       * failure: the write was refused on purpose and the caller must carry
+       * on with the rest of its batch. Every caller narrows on this status
+       * because it carries no `row` — the compiler is what makes a future
+       * provider handle it rather than dereference a row that does not exist.
+       */
+      status: "rejected_range";
+      rejection: MeasurementRangeRejection;
     };
 
 export type FailedMeasurementReconciliation = Extract<
@@ -219,12 +236,26 @@ async function retireCollision(
  * advisory lock serializes cooperative writers sharing either identity, and a
  * savepoint turns a non-benign database error into a structured `failed`
  * verdict without poisoning the caller's surrounding transaction.
+ *
+ * This is also the plausibility gate for every provider that reconciles rather
+ * than writing Prisma directly. Gating HERE rather than at each caller is the
+ * point: a provider added tomorrow inherits the refusal by construction, and
+ * cannot land an impossible reading by forgetting a check it never knew about.
  */
 export async function reconcileExternalMeasurement(
   tx: PrismaTypes.TransactionClient,
   desired: ExternalMeasurementWrite,
   options: MeasurementReconciliationOptions = {},
 ): Promise<MeasurementReconciliationVerdict> {
+  const rejection = classifyRangeRejection(desired.type, desired.value);
+  if (rejection) {
+    recordRangeRejections(
+      desired.source ? String(desired.source).toLowerCase() : "external",
+      [rejection],
+    );
+    return { status: "rejected_range", rejection };
+  }
+
   await tx.$executeRawUnsafe(`SAVEPOINT ${SAVEPOINT}`);
 
   try {
diff --git a/src/lib/nightscout/__tests__/sync-plausibility.test.ts b/src/lib/nightscout/__tests__/sync-plausibility.test.ts
new file mode 100644
index 000000000..24c023eb7
--- /dev/null
+++ b/src/lib/nightscout/__tests__/sync-plausibility.test.ts
@@ -0,0 +1,115 @@
+/**
+ * The Nightscout pull writes BLOOD_GLUCOSE rows directly, so it does not
+ * inherit the shared reconciler's gate. It is also first-write-wins: a row
+ * that lands here is immutable, so an impossible sample never corrects itself
+ * on a later pass. These cases pin the refusal and its annotation.
+ */
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+const {
+  upsertMock,
+  findManyMock,
+  emitArrivalsMock,
+  recomputeMock,
+  invalidateMock,
+} = vi.hoisted(() => ({
+  upsertMock: vi.fn(),
+  findManyMock: vi.fn(),
+  emitArrivalsMock: vi.fn(),
+  recomputeMock: vi.fn(),
+  invalidateMock: vi.fn(),
+}));
+
+vi.mock("@/lib/db", () => ({
+  prisma: { measurement: { upsert: upsertMock, findMany: findManyMock } },
+}));
+
+vi.mock("@/lib/arrivals/measurement-emit", () => ({
+  emitInsertedMeasurementArrivals: emitArrivalsMock,
+}));
+
+vi.mock("@/lib/rollups/measurement-rollups", () => ({
+  collapseToTypeDayKeys: (rows: Array<{ type: string; measuredAt: Date }>) =>
+    rows.map((r) => ({ type: r.type, measuredAt: r.measuredAt })),
+  recomputeBucketsForMeasurement: recomputeMock,
+}));
+
+vi.mock("@/lib/insights/comprehensive-generate", () => ({
+  invalidateStatusInsightsForTypes: invalidateMock,
+}));
+
+import { eventStorage } from "@/lib/logging/context";
+import { WideEventBuilder } from "@/lib/logging/event-builder";
+import { RANGE_REJECTED_META_KEY } from "@/lib/measurements/plausibility-gate";
+import type { RangeRejectionTally } from "@/lib/measurements/plausibility-gate";
+
+import { upsertNightscoutEntries } from "../sync";
+
+/** BLOOD_GLUCOSE is declared 20–800 mg/dL. */
+const REAL_ENTRY = { id: "abc", sgv: 112, date: 1718000000000 };
+/** A sensor fault, or an mg/dL field carrying something else entirely. */
+const IMPOSSIBLE_ENTRY = { id: "def", sgv: 41_600, date: 1718000300000 };
+
+let event: WideEventBuilder;
+
+function tally(): RangeRejectionTally | undefined {
+  return event.toJSON().meta?.[RANGE_REJECTED_META_KEY] as
+    RangeRejectionTally | undefined;
+}
+
+beforeEach(() => {
+  vi.clearAllMocks();
+  findManyMock.mockResolvedValue([]);
+  upsertMock.mockResolvedValue({ id: "row-1" });
+  emitArrivalsMock.mockResolvedValue(undefined);
+  recomputeMock.mockResolvedValue(undefined);
+  invalidateMock.mockResolvedValue(undefined);
+  event = new WideEventBuilder("background");
+});
+
+describe("upsertNightscoutEntries — plausibility gate", () => {
+  it("writes a reading inside the metric's declared band", async () => {
+    const result = await eventStorage.run(event, () =>
+      upsertNightscoutEntries("user-1", [REAL_ENTRY]),
+    );
+
+    expect(result).toEqual({ inserted: 1, failedRows: 0 });
+    expect(upsertMock).toHaveBeenCalledTimes(1);
+    expect(tally()).toBeUndefined();
+  });
+
+  it("refuses an out-of-band reading and annotates the drop", async () => {
+    const result = await eventStorage.run(event, () =>
+      upsertNightscoutEntries("user-1", [REAL_ENTRY, IMPOSSIBLE_ENTRY]),
+    );
+
+    expect(result).toEqual({ inserted: 1, failedRows: 0 });
+    expect(upsertMock).toHaveBeenCalledTimes(1);
+    expect(
+      (upsertMock.mock.calls[0]![0] as { create: { value: number } }).create
+        .value,
+    ).toBe(112);
+    expect(tally()).toEqual({
+      total: 1,
+      buckets: [
+        {
+          source: "nightscout",
+          type: "BLOOD_GLUCOSE",
+          direction: "above_max",
+          count: 1,
+        },
+      ],
+    });
+    expect(event.getLevel()).toBe("warn");
+  });
+
+  it("writes nothing when the whole page is out of band", async () => {
+    const result = await eventStorage.run(event, () =>
+      upsertNightscoutEntries("user-1", [IMPOSSIBLE_ENTRY]),
+    );
+
+    expect(result).toEqual({ inserted: 0, failedRows: 0 });
+    expect(upsertMock).not.toHaveBeenCalled();
+    expect(tally()?.total).toBe(1);
+  });
+});
diff --git a/src/lib/nightscout/sync.ts b/src/lib/nightscout/sync.ts
index adef2de55..f92104550 100644
--- a/src/lib/nightscout/sync.ts
+++ b/src/lib/nightscout/sync.ts
@@ -22,6 +22,7 @@
 import { prisma } from "@/lib/db";
 import type { MeasurementType } from "@/generated/prisma/client";
 import { getEvent } from "@/lib/logging/context";
+import { dropImplausibleMeasurements } from "@/lib/measurements/plausibility-gate";
 import {
   markSyncFailureRecorded,
   recordSyncFailure,
@@ -221,7 +222,16 @@ export async function upsertNightscoutEntries(
   if (entries.length === 0) return { inserted: 0, failedRows: 0 };
 
   const type = "BLOOD_GLUCOSE" as MeasurementType;
-  const mapped = entries.map((entry) => mapSgvEntryToMeasurement(entry));
+  // A CGM that reports a glucose the app's own band calls impossible is
+  // reporting a sensor fault or a unit slip, not a reading. Drop it: the row
+  // would otherwise be immutable (first-write-wins), so an impossible sample
+  // that lands here never corrects itself on a later pass.
+  const mapped = dropImplausibleMeasurements(
+    "nightscout",
+    entries.map((entry) => mapSgvEntryToMeasurement(entry)),
+    (m) => ({ type, value: m.value }),
+  );
+  if (mapped.length === 0) return { inserted: 0, failedRows: 0 };
 
   // Probe which keys already exist so a re-confirmed reading (the upsert's
   // no-op update branch) is not miscounted as a fresh import and the arrival
diff --git a/src/lib/openapi/routes/labs.ts b/src/lib/openapi/routes/labs.ts
index ce310b3e1..849518f32 100644
--- a/src/lib/openapi/routes/labs.ts
+++ b/src/lib/openapi/routes/labs.ts
@@ -44,7 +44,13 @@ listLabResultsSchema.meta({
 const rangeStatusEnum = z.enum(["in-range", "below", "above", "unknown"]).meta({
   id: "LabReferenceRangeStatus",
   description:
-    "Server-computed, NEUTRAL reference-range verdict. `unknown` when the lab reported no usable bounds. Inclusive bounds: a value on the limit reads in-range. The badge that renders this must stay calm and informative — not an alarming red.",
+    "Server-computed, NEUTRAL reference-range verdict, always against `referenceLow` / `referenceHigh` (the window in force for that reading). `unknown` when no usable bounds are on file. Inclusive bounds: a value on the limit reads in-range. The badge that renders this must stay calm and informative — not an alarming red.",
+});
+
+const referenceOriginEnum = z.enum(["source", "catalog", "none"]).meta({
+  id: "LabReferenceRangeOrigin",
+  description:
+    "Which window `referenceLow` / `referenceHigh` came from. `source` = the range printed on this reading's own report, which wins for that reading because it is the window the physician evaluated the value against. `catalog` = the user's Biomarker band, the net for readings with no printed range. `none` = no window on file.",
 });
 
 const labResultRow = z
@@ -60,6 +66,13 @@ const labResultRow = z
     unit: z.string(),
     referenceLow: z.number().nullable(),
     referenceHigh: z.number().nullable(),
+    catalogReferenceLow: z.number().nullable(),
+    catalogReferenceHigh: z.number().nullable(),
+    sourceReferenceLow: z.number().nullable(),
+    sourceReferenceHigh: z.number().nullable(),
+    sourceReferenceText: z.string().nullable(),
+    referenceOrigin: referenceOriginEnum,
+    referenceDivergesFromCatalog: z.boolean(),
     takenAt: z.string(),
     source: z.string(),
     hasNote: z.boolean(),
@@ -70,7 +83,7 @@ const labResultRow = z
   .meta({
     id: "LabResult",
     description:
-      'A stored lab result. Exactly one of `value` (numeric) or `valueText` (qualitative, e.g. "negativ") is non-null; `rangeStatus` is always `unknown` for a qualitative row (no number to classify). `biomarkerId` links the user-scoped catalog marker (null for legacy free-text rows); when linked, `analyte` / `unit` / `referenceLow` / `referenceHigh` are RESOLVED server-side from the Biomarker — the client renders them and never recomputes the range. The encrypted note is never echoed in list rows; `hasNote` flags its presence and the single-resource GET returns the decrypted `note`.',
+      "A stored lab result. Exactly one of `value` (numeric) or `valueText` (qualitative, e.g. \"negativ\") is non-null; `rangeStatus` is always `unknown` for a qualitative row (no number to classify). `biomarkerId` links the user-scoped catalog marker (null for legacy free-text rows); when linked, `analyte` / `unit` are RESOLVED server-side from the Biomarker.\n\nThree reference windows ride on the row and the server says which one applies. `referenceLow` / `referenceHigh` are the window IN FORCE and the one `rangeStatus` was computed from — read these to render the range and you are correct without doing any resolution of your own. `sourceReferenceLow` / `sourceReferenceHigh` / `sourceReferenceText` are the range this reading's own report printed (the text verbatim, kept even when no numbers could be read out of it). `catalogReferenceLow` / `catalogReferenceHigh` are the Biomarker band. `referenceOrigin` names the winner and `referenceDivergesFromCatalog` is true when the report's window and the catalog band state different limits — a surface showing only one of the two is showing a partial answer. The client renders these values and never recomputes the range. The encrypted note is never echoed in list rows; `hasNote` flags its presence and the single-resource GET returns the decrypted `note`.",
   });
 
 const labResultDetail = labResultRow
diff --git a/src/lib/openapi/routes/ocr.ts b/src/lib/openapi/routes/ocr.ts
index 2493c1f56..90baa89d3 100644
--- a/src/lib/openapi/routes/ocr.ts
+++ b/src/lib/openapi/routes/ocr.ts
@@ -53,6 +53,10 @@ const extractedRow = z
     unit: z.string().nullable(),
     referenceLow: z.number().nullable(),
     referenceHigh: z.number().nullable(),
+    referenceText: z.string().nullable().meta({
+      description:
+        'The reference range EXACTLY as printed on the report, verbatim ("3,5 - 5,0", "< 116", "bis 5,0", "negativ"). `referenceLow` / `referenceHigh` carry the same window reduced to numbers WHEN it reduces to numbers; this field carries it either way, so a window stated in words is not lost between the report and the reading.',
+    }),
     takenAt: z.string().nullable(),
     confidence: extractConfidence,
     biomarkerMatch: z.enum(["new", "existing"]),
@@ -87,6 +91,13 @@ const committedRow = z
     unit: z.string(),
     referenceLow: z.number().nullable(),
     referenceHigh: z.number().nullable(),
+    catalogReferenceLow: z.number().nullable(),
+    catalogReferenceHigh: z.number().nullable(),
+    sourceReferenceLow: z.number().nullable(),
+    sourceReferenceHigh: z.number().nullable(),
+    sourceReferenceText: z.string().nullable(),
+    referenceOrigin: z.enum(["source", "catalog", "none"]),
+    referenceDivergesFromCatalog: z.boolean(),
     takenAt: z.string(),
     source: z.string(),
     hasNote: z.boolean(),
@@ -94,7 +105,11 @@ const committedRow = z
     createdAt: z.string(),
     updatedAt: z.string(),
   })
-  .meta({ id: "OcrCommittedLabResult" });
+  .meta({
+    id: "OcrCommittedLabResult",
+    description:
+      "A written reading. Its reference window resolves exactly as it does on `/api/labs` — see `LabResult`.",
+  });
 
 const commitResponse = z
   .object({
diff --git a/src/lib/oura/sync.ts b/src/lib/oura/sync.ts
index 4dfefaa83..aa11c88f5 100644
--- a/src/lib/oura/sync.ts
+++ b/src/lib/oura/sync.ts
@@ -575,6 +575,10 @@ export async function upsertOuraMeasurements(
   for (let index = 0; index < readings.length; index++) {
     const reading = readings[index]!;
     const verdict = verdicts[index]!;
+    // Refused by the plausibility gate: nothing was written and nothing was
+    // touched, so the reading counts as neither imported nor a rollup dirt
+    // mark. The drop is already on the wide event.
+    if (verdict.status === "rejected_range") continue;
     for (const dirty of verdict.dirtyIdentities ?? []) {
       touched.push(dirty);
     }
diff --git a/src/lib/polar/sync.ts b/src/lib/polar/sync.ts
index 17b6505c5..8b44200fe 100644
--- a/src/lib/polar/sync.ts
+++ b/src/lib/polar/sync.ts
@@ -364,6 +364,10 @@ export async function upsertPolarMeasurements(
   for (let index = 0; index < readings.length; index++) {
     const reading = readings[index]!;
     const verdict = verdicts[index]!;
+    // Refused by the plausibility gate: nothing was written and nothing was
+    // touched, so the reading counts as neither imported nor a rollup dirt
+    // mark. The drop is already on the wide event.
+    if (verdict.status === "rejected_range") continue;
     for (const dirty of verdict.dirtyIdentities ?? []) {
       touched.push(dirty);
     }
diff --git a/src/lib/validations/backup.ts b/src/lib/validations/backup.ts
index 374847ed1..b8f671448 100644
--- a/src/lib/validations/backup.ts
+++ b/src/lib/validations/backup.ts
@@ -717,6 +717,11 @@ const labResultBackupSchema = z
     unit: z.string().min(1),
     referenceLow: z.number().nullable().optional(),
     referenceHigh: z.number().nullable().optional(),
+    // Optional so a backup written before these columns existed still
+    // restores; absent reads as "this reading had no source window on file".
+    sourceReferenceLow: z.number().nullable().optional(),
+    sourceReferenceHigh: z.number().nullable().optional(),
+    sourceReferenceText: z.string().nullable().optional(),
     takenAt: isoDateTime,
     source: z.string().min(1),
     biomarkerName: z.string().nullable().optional(),
diff --git a/src/lib/validations/inbound-documents.ts b/src/lib/validations/inbound-documents.ts
index cf59d774d..31cfce53e 100644
--- a/src/lib/validations/inbound-documents.ts
+++ b/src/lib/validations/inbound-documents.ts
@@ -167,6 +167,15 @@ export const extractedFactRawSchema = z.object({
   unit: nullableText(80),
   referenceLow: z.number().finite().nullable().catch(null),
   referenceHigh: z.number().finite().nullable().catch(null),
+  /**
+   * Observation: the reference range EXACTLY as printed, verbatim. A report
+   * writes its window in prose ("3,5 - 5,0", "< 5", "bis 5,0", "negativ"), and
+   * `referenceLow` / `referenceHigh` above can only carry the cases that
+   * reduce to two numbers. This field is what stops every other case from
+   * being dropped on the floor — the string is kept whether or not the parser
+   * gets bounds out of it.
+   */
+  referenceText: nullableText(120),
   /** MedicationStatement: dose + stated status (verbatim). */
   dose: nullableText(120),
   medicationStatus: nullableText(64),
@@ -237,6 +246,14 @@ export interface ObservationFactData {
   unit: string | null;
   referenceLow: number | null;
   referenceHigh: number | null;
+  /**
+   * The reference range as printed on the report, verbatim.
+   *
+   * Optional because it genuinely is: a fact staged before this field existed
+   * carries no key for it, and that is an honest absence rather than a shim
+   * for a caller we do not ship. Read it as `?? null`.
+   */
+  referenceText?: string | null;
   effectiveDate: string | null;
 }
 
@@ -379,6 +396,7 @@ const observationEditSchema = z
     unit: optText(80),
     referenceLow: z.number().finite().nullable().optional(),
     referenceHigh: z.number().finite().nullable().optional(),
+    referenceText: optText(120),
     effectiveDate: isoDate,
   })
   // Numeric XOR qualitative, mirroring the lab-result discipline. A null/absent
diff --git a/src/lib/validations/labs-ocr.ts b/src/lib/validations/labs-ocr.ts
index e9f3ff516..e79843f8b 100644
--- a/src/lib/validations/labs-ocr.ts
+++ b/src/lib/validations/labs-ocr.ts
@@ -78,6 +78,13 @@ export const extractedRowSchema = z.object({
   unit: z.string().trim().max(80).nullable().catch(null),
   referenceLow: z.number().finite().nullable().catch(null),
   referenceHigh: z.number().finite().nullable().catch(null),
+  /**
+   * The reference range EXACTLY as printed, verbatim. The two numeric bounds
+   * above can only carry a window that reduces to two numbers; a report that
+   * prints "bis 5,0" or "negativ" states a window all the same, and this is
+   * what keeps it instead of dropping it.
+   */
+  referenceText: z.string().trim().max(120).nullable().catch(null),
   takenAt: z.string().nullable().catch(null),
   confidence: extractedConfidenceSchema,
 });
@@ -107,6 +114,8 @@ export interface OcrExtractedRowDto {
   unit: string | null;
   referenceLow: number | null;
   referenceHigh: number | null;
+  /** The reference range as printed on the report, verbatim. */
+  referenceText: string | null;
   takenAt: string | null;
   confidence: {
     analyte: number;
@@ -150,6 +159,17 @@ export const ocrCommitRowSchema = z
     unit: z.string().trim().min(1).max(40).optional(),
     referenceLow,
     referenceHigh,
+    /**
+     * The window the scanned report printed for this row. Confirmed by the
+     * human on the review screen alongside everything else, and written onto
+     * the reading rather than only used to seed a new catalog marker.
+     */
+    referenceText: z
+      .string()
+      .trim()
+      .max(120)
+      .optional()
+      .or(z.literal("").transform(() => undefined)),
     takenAt: takenAtField,
   })
   // Numeric XOR qualitative: exactly one of value / valueText.
diff --git a/src/lib/validations/labs.ts b/src/lib/validations/labs.ts
index 7f0c53c8f..c3b77b8c0 100644
--- a/src/lib/validations/labs.ts
+++ b/src/lib/validations/labs.ts
@@ -14,6 +14,7 @@
  */
 import { z } from "zod/v4";
 
+import { SOURCE_REFERENCE_TEXT_MAX } from "@/lib/labs/parse-reference-range";
 import { validateEntryInstant } from "@/lib/validations/entry-instant";
 
 /**
@@ -63,6 +64,29 @@ const optionalNote = z
 const referenceLow = z.number().finite().optional();
 const referenceHigh = z.number().finite().optional();
 
+/**
+ * The reference range the SOURCE REPORT printed for this one reading.
+ *
+ * Distinct from `referenceLow` / `referenceHigh` above, which seed (and are
+ * stamped from) the catalog marker's band. A lab runs its own method on its
+ * own device, so the window a physician evaluates against is the one on that
+ * report; these fields carry it, and `resolveEffectiveReferenceRange` lets it
+ * win for that reading alone.
+ *
+ * `sourceReferenceText` is what was printed, verbatim. It is accepted with or
+ * without derivable bounds: a window stated as "negativ" or "siehe Befund"
+ * still belongs on the record, and dropping it because no number could be read
+ * out of it is exactly the loss this field exists to stop.
+ */
+const sourceReferenceLow = z.number().finite().optional();
+const sourceReferenceHigh = z.number().finite().optional();
+const sourceReferenceText = z
+  .string()
+  .trim()
+  .max(SOURCE_REFERENCE_TEXT_MAX)
+  .optional()
+  .or(z.literal("").transform(() => undefined));
+
 /**
  * v1.18.1 — optional link to a user-scoped `Biomarker` (the catalog row).
  * When set, the structured-entry path resolves the unit + reference range
@@ -101,6 +125,9 @@ export const createLabResultSchema = z
     unit: requiredText(40).optional(),
     referenceLow,
     referenceHigh,
+    sourceReferenceLow,
+    sourceReferenceHigh,
+    sourceReferenceText,
     takenAt: takenAtField,
     note: optionalNote,
     source,
@@ -142,6 +169,19 @@ export const createLabResultSchema = z
       message: "referenceLow must not exceed referenceHigh",
       path: ["referenceLow"],
     },
+  )
+  // Same guard on the source window. A transposed window is a client error
+  // here for the same reason: nothing downstream can tell it from a real one.
+  .refine(
+    (d) =>
+      d.valueText !== undefined ||
+      d.sourceReferenceLow === undefined ||
+      d.sourceReferenceHigh === undefined ||
+      d.sourceReferenceLow <= d.sourceReferenceHigh,
+    {
+      message: "sourceReferenceLow must not exceed sourceReferenceHigh",
+      path: ["sourceReferenceLow"],
+    },
   );
 
 export type CreateLabResultInput = z.infer<typeof createLabResultSchema>;
@@ -164,6 +204,9 @@ export const updateLabResultSchema = z
     unit: requiredText(40).optional(),
     referenceLow: referenceLow.or(z.null()),
     referenceHigh: referenceHigh.or(z.null()),
+    sourceReferenceLow: sourceReferenceLow.or(z.null()),
+    sourceReferenceHigh: sourceReferenceHigh.or(z.null()),
+    sourceReferenceText: sourceReferenceText.or(z.null()),
     takenAt: takenAtField.optional(),
     note: optionalNote.or(z.null()),
   })
@@ -183,6 +226,18 @@ export const updateLabResultSchema = z
       message: "referenceLow must not exceed referenceHigh",
       path: ["referenceLow"],
     },
+  )
+  .refine(
+    (d) =>
+      d.sourceReferenceLow === undefined ||
+      d.sourceReferenceLow === null ||
+      d.sourceReferenceHigh === undefined ||
+      d.sourceReferenceHigh === null ||
+      d.sourceReferenceLow <= d.sourceReferenceHigh,
+    {
+      message: "sourceReferenceLow must not exceed sourceReferenceHigh",
+      path: ["sourceReferenceLow"],
+    },
   );
 
 export type UpdateLabResultInput = z.infer<typeof updateLabResultSchema>;
@@ -246,7 +301,12 @@ export type ListLabResultsInput = z.infer<typeof listLabResultsSchema>;
  * implementation. Re-exported here for the existing import sites.
  */
 export {
+  classifyAgainstEffectiveRange,
   classifyReferenceRange,
   formatReferenceRange,
+  resolveEffectiveReferenceRange,
+  type EffectiveReferenceRange,
+  type ReferenceRangeOrigin,
   type ReferenceRangeStatus,
+  type SourceReferenceRange,
 } from "@/lib/labs/reference-range";
diff --git a/src/lib/whoop/sync-core.ts b/src/lib/whoop/sync-core.ts
index 2e2e41212..464ab6718 100644
--- a/src/lib/whoop/sync-core.ts
+++ b/src/lib/whoop/sync-core.ts
@@ -480,6 +480,10 @@ export async function upsertWhoopMeasurements(
     for (let index = chunkStart; index < chunkEnd; index++) {
       const reading = readings[index]!;
       const verdict = verdicts[index - chunkStart]!;
+      // Refused by the plausibility gate: nothing was written and nothing was
+      // touched, so the reading counts as neither imported nor a rollup dirt
+      // mark. The drop is already on the wide event.
+      if (verdict.status === "rejected_range") continue;
       for (const dirty of verdict.dirtyIdentities ?? []) {
         touched.push(dirty);
         touchedTypes.add(dirty.type);
diff --git a/src/lib/withings/__tests__/sync-plausibility.test.ts b/src/lib/withings/__tests__/sync-plausibility.test.ts
new file mode 100644
index 000000000..8aa7572c7
--- /dev/null
+++ b/src/lib/withings/__tests__/sync-plausibility.test.ts
@@ -0,0 +1,261 @@
+/**
+ * Withings writes the measurement table directly — the measures leg row by
+ * row, the activity leg as a planned batch — so neither inherits the shared
+ * reconciler's gate. These cases pin that both legs now clear the app's own
+ * declared plausibility band before anything reaches Prisma, and that a
+ * refusal lands on the wide event rather than vanishing.
+ *
+ * The measures leg matters twice over: it does not only insert, it OVERWRITES
+ * the stored value of an existing slot, so an ungated impossible reading could
+ * replace a real one.
+ */
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+vi.mock("@/lib/db", () => ({
+  prisma: {
+    measurement: {
+      findFirst: vi.fn(),
+      findMany: vi.fn(),
+      create: vi.fn(),
+      createMany: vi.fn(),
+      update: vi.fn(),
+    },
+    withingsConnection: {
+      findUnique: vi.fn(),
+      update: vi.fn(),
+    },
+    $queryRaw: vi.fn(),
+    $transaction: vi.fn((ops: unknown) =>
+      Array.isArray(ops) ? Promise.all(ops) : Promise.resolve(),
+    ),
+  },
+}));
+
+vi.mock("@/lib/crypto", () => ({
+  decrypt: vi.fn((v: string) => v),
+  encrypt: vi.fn((v: string) => v),
+}));
+
+vi.mock("../client", async () => {
+  const actual = await vi.importActual<typeof import("../client")>("../client");
+  return {
+    ...actual,
+    fetchMeasurements: vi.fn(),
+    refreshAccessToken: vi.fn(),
+    subscribeWebhook: vi.fn(),
+  };
+});
+
+vi.mock("../credentials", () => ({
+  getUserWithingsCredentials: vi.fn(async () => ({
+    clientId: "cid",
+    clientSecret: "secret",
+  })),
+}));
+
+vi.mock("@/lib/integrations/status", () => ({
+  isReauthRequired: vi.fn().mockResolvedValue(false),
+  parkIntegrationAtReauth: vi.fn(),
+  recordSyncFailure: vi.fn().mockResolvedValue(undefined),
+  recordSyncSuccess: vi.fn().mockResolvedValue(undefined),
+}));
+
+vi.mock("@/lib/rollups/measurement-rollups", async () => {
+  const actual = await vi.importActual<
+    typeof import("@/lib/rollups/measurement-rollups")
+  >("@/lib/rollups/measurement-rollups");
+  return {
+    ...actual,
+    recomputeBucketsForMeasurement: vi.fn().mockResolvedValue(undefined),
+  };
+});
+
+vi.mock("@/lib/insights/comprehensive-generate", () => ({
+  invalidateStatusInsightsForTypes: vi.fn().mockResolvedValue(undefined),
+}));
+
+vi.mock("@/lib/cache/invalidate", () => ({
+  invalidateUserDashboardSnapshot: vi.fn(),
+}));
+
+import { prisma } from "@/lib/db";
+import { eventStorage } from "@/lib/logging/context";
+import { WideEventBuilder } from "@/lib/logging/event-builder";
+import { RANGE_REJECTED_META_KEY } from "@/lib/measurements/plausibility-gate";
+import type { RangeRejectionTally } from "@/lib/measurements/plausibility-gate";
+
+import { fetchMeasurements } from "../client";
+import { syncUserActivity } from "../sync-activity";
+import { syncUserMeasurements } from "../sync";
+
+let event: WideEventBuilder;
+
+function tally(): RangeRejectionTally | undefined {
+  return event.toJSON().meta?.[RANGE_REJECTED_META_KEY] as
+    RangeRejectionTally | undefined;
+}
+
+function installActivityFetch(
+  entries: Array<{ date: string; steps?: number; distance?: number }>,
+) {
+  vi.stubGlobal(
+    "fetch",
+    vi.fn(async () => ({
+      status: 200,
+      headers: new Headers(),
+      json: async () => ({
+        status: 0,
+        body: { activities: entries, more: false, offset: 0 },
+      }),
+    })),
+  );
+}
+
+beforeEach(() => {
+  vi.clearAllMocks();
+  event = new WideEventBuilder("background");
+  vi.mocked(prisma.withingsConnection.findUnique).mockResolvedValue({
+    id: "conn-1",
+    withingsUserId: "wu-1",
+    accessToken: "enc-access",
+    refreshToken: "enc-refresh",
+    scope: "user.metrics,user.activity",
+    tokenExpiresAt: new Date(Date.now() + 60 * 60 * 1000),
+    lastSyncedAt: new Date(Date.now() - 60 * 60 * 1000),
+  } as never);
+  vi.mocked(prisma.withingsConnection.update).mockResolvedValue({} as never);
+  vi.mocked(prisma.measurement.findFirst).mockResolvedValue(null);
+  vi.mocked(prisma.measurement.findMany).mockResolvedValue([] as never);
+  vi.mocked(prisma.measurement.create).mockResolvedValue({
+    id: "m-1",
+    type: "PULSE",
+    measuredAt: new Date(),
+  } as never);
+  vi.mocked(prisma.measurement.createMany).mockResolvedValue({
+    count: 1,
+  } as never);
+  vi.mocked(prisma.measurement.update).mockResolvedValue({} as never);
+});
+
+afterEach(() => {
+  vi.unstubAllGlobals();
+});
+
+describe("syncUserMeasurements — plausibility gate", () => {
+  it("writes a reading inside the metric's declared band", async () => {
+    vi.mocked(fetchMeasurements).mockResolvedValue([
+      {
+        type: "PULSE",
+        value: 112,
+        measuredAt: new Date("2026-05-16T08:00:00Z"),
+      },
+    ] as never);
+
+    const result = await eventStorage.run(event, () =>
+      syncUserMeasurements("user-1"),
+    );
+
+    expect(result).toEqual({ imported: 1, failed: false });
+    expect(prisma.measurement.create).toHaveBeenCalledTimes(1);
+    expect(tally()).toBeUndefined();
+  });
+
+  it("refuses an out-of-band reading and annotates the drop", async () => {
+    vi.mocked(fetchMeasurements).mockResolvedValue([
+      {
+        type: "PULSE",
+        value: 112,
+        measuredAt: new Date("2026-05-16T08:00:00Z"),
+      },
+      {
+        type: "PULSE",
+        value: 55643821.505,
+        measuredAt: new Date("2026-05-16T08:05:00Z"),
+      },
+    ] as never);
+
+    const result = await eventStorage.run(event, () =>
+      syncUserMeasurements("user-1"),
+    );
+
+    // Only the real reading landed, and the run is still a clean success: one
+    // impossible sample must not strand the rest behind a held watermark.
+    expect(result).toEqual({ imported: 1, failed: false });
+    expect(prisma.measurement.create).toHaveBeenCalledTimes(1);
+    expect(tally()).toEqual({
+      total: 1,
+      buckets: [
+        { source: "withings", type: "PULSE", direction: "above_max", count: 1 },
+      ],
+    });
+    expect(event.getLevel()).toBe("warn");
+  });
+
+  it("does not overwrite a stored reading with an out-of-band one", async () => {
+    // The slot already holds a real pulse; the provider re-sends the same
+    // instant carrying a decode slip. Ungated, the update branch rewrote the
+    // good value with the bad one.
+    vi.mocked(prisma.measurement.findFirst).mockResolvedValue({
+      id: "existing-row",
+    } as never);
+    vi.mocked(fetchMeasurements).mockResolvedValue([
+      {
+        type: "PULSE",
+        value: 55643821.505,
+        measuredAt: new Date("2026-05-16T08:00:00Z"),
+      },
+    ] as never);
+
+    const result = await eventStorage.run(event, () =>
+      syncUserMeasurements("user-1"),
+    );
+
+    expect(result).toEqual({ imported: 0, failed: false });
+    expect(prisma.measurement.update).not.toHaveBeenCalled();
+    expect(tally()?.total).toBe(1);
+  });
+});
+
+describe("syncUserActivity — plausibility gate", () => {
+  it("plans a daily total inside the metric's declared band", async () => {
+    installActivityFetch([{ date: "2026-05-16", steps: 8_400 }]);
+
+    const imported = await eventStorage.run(event, () =>
+      syncUserActivity("user-1"),
+    );
+
+    expect(imported).toBe(1);
+    expect(prisma.measurement.createMany).toHaveBeenCalledTimes(1);
+    expect(tally()).toBeUndefined();
+  });
+
+  it("refuses an out-of-band daily total and annotates the drop", async () => {
+    // ACTIVITY_STEPS is declared 0–200 000.
+    installActivityFetch([
+      { date: "2026-05-16", steps: 8_400 },
+      { date: "2026-05-17", steps: 9_900_000 },
+    ]);
+
+    const imported = await eventStorage.run(event, () =>
+      syncUserActivity("user-1"),
+    );
+
+    expect(imported).toBe(1);
+    const created = vi.mocked(prisma.measurement.createMany).mock.calls[0]?.[0]
+      ?.data as Array<{ value: number }>;
+    expect(created).toHaveLength(1);
+    expect(created[0]!.value).toBe(8_400);
+    expect(tally()).toEqual({
+      total: 1,
+      buckets: [
+        {
+          source: "withings",
+          type: "ACTIVITY_STEPS",
+          direction: "above_max",
+          count: 1,
+        },
+      ],
+    });
+    expect(event.getLevel()).toBe("warn");
+  });
+});
diff --git a/src/lib/withings/sync-activity.ts b/src/lib/withings/sync-activity.ts
index 869fb1d18..a4a0098b2 100644
--- a/src/lib/withings/sync-activity.ts
+++ b/src/lib/withings/sync-activity.ts
@@ -39,6 +39,7 @@ import { prisma } from "@/lib/db";
 import { getEvent } from "@/lib/logging/context";
 import { safeFetch } from "@/lib/safe-fetch";
 import { getUnitForType } from "@/lib/validations/measurement";
+import { dropImplausibleMeasurements } from "@/lib/measurements/plausibility-gate";
 import {
   collapseToTypeDayKeys,
   recomputeBucketsForMeasurement,
@@ -342,7 +343,7 @@ export async function syncUserActivity(
     value: number;
     externalId: string;
   }
-  const planned: PlannedRow[] = [];
+  const collected: PlannedRow[] = [];
   for (const entry of entries) {
     if (!entry.date) continue;
     const measuredAt = activityMeasuredAt(entry.date);
@@ -352,7 +353,7 @@ export async function syncUserActivity(
       // valid (a day of rest still records 0 steps). Only skip
       // undefined / null / NaN.
       if (raw == null || !Number.isFinite(raw)) continue;
-      planned.push({
+      collected.push({
         type,
         measuredAt,
         value: raw,
@@ -361,6 +362,15 @@ export async function syncUserActivity(
     }
   }
 
+  // A daily-activity total the app's own band calls impossible (a step count
+  // past 200 000, a negative distance) is a provider artefact, not a day. Drop
+  // it before the plan is read against the table, so it can neither insert a
+  // fresh impossible slot nor overwrite a good stored one.
+  const planned = dropImplausibleMeasurements("withings", collected, (p) => ({
+    type: p.type,
+    value: p.value,
+  }));
+
   if (planned.length > 0) {
     const slotKey = (type: MeasurementType, measuredAt: Date) =>
       `${type}|${measuredAt.getTime()}`;
diff --git a/src/lib/withings/sync-sleep.ts b/src/lib/withings/sync-sleep.ts
index 840b5d8d3..65099ea7c 100644
--- a/src/lib/withings/sync-sleep.ts
+++ b/src/lib/withings/sync-sleep.ts
@@ -474,6 +474,9 @@ export async function syncUserSleep(
           if (verdict.status === "failed") {
             throw new MeasurementReconciliationError(verdict);
           }
+          // Refused by the plausibility gate: nothing was written and nothing
+          // was touched. The drop is already on the wide event.
+          if (verdict.status === "rejected_range") continue;
           for (const dirty of verdict.dirtyIdentities ?? []) {
             touched.push(dirty);
           }
@@ -542,6 +545,9 @@ export async function syncUserSleep(
             if (verdict.status === "failed") {
               throw new MeasurementReconciliationError(verdict);
             }
+            // Refused by the plausibility gate: nothing was written and
+            // nothing was touched. The drop is already on the wide event.
+            if (verdict.status === "rejected_range") continue;
             for (const dirty of verdict.dirtyIdentities ?? []) {
               touched.push(dirty);
             }
diff --git a/src/lib/withings/sync.ts b/src/lib/withings/sync.ts
index fcee1cc7c..d500a030c 100644
--- a/src/lib/withings/sync.ts
+++ b/src/lib/withings/sync.ts
@@ -15,6 +15,7 @@ import { getUserWithingsCredentials } from "./credentials";
 import { annotate, getEvent } from "@/lib/logging/context";
 import { isP2002 } from "@/lib/prisma-errors";
 import { emitInsertedMeasurementArrivals } from "@/lib/arrivals/measurement-emit";
+import { dropImplausibleMeasurements } from "@/lib/measurements/plausibility-gate";
 import {
   isReauthRequired,
   recordSyncFailure,
@@ -229,14 +230,24 @@ export async function syncUserMeasurements(
         )
       : new Date(Date.now() - 30 * 24 * 60 * 60 * 1000); // 30 days back
 
-  let measures: Awaited<ReturnType<typeof fetchMeasurements>>;
+  let fetched: Awaited<ReturnType<typeof fetchMeasurements>>;
   try {
-    measures = await fetchMeasurements(tokenInfo.accessToken, startDate);
+    fetched = await fetchMeasurements(tokenInfo.accessToken, startDate);
   } catch (err) {
     await recordWithingsSyncFailure(userId, err, WITHINGS_LEG_MEASURES);
     throw err;
   }
 
+  // The app's own plausibility band applies to a provider reading exactly as
+  // it applies to a typed one. A remote that reports a pulse in the millions
+  // is reporting a decode slip, not a heartbeat, and the row would poison
+  // every mean and personal band derived from it. Refuse it here, before the
+  // update branch below can overwrite a good stored value with it.
+  const measures = dropImplausibleMeasurements("withings", fetched, (m) => ({
+    type: m.type,
+    value: m.value,
+  }));
+
   let imported = 0;
   // v1.4.39.1 — track every (type, measuredAt) we touched so the
   // persistent rollup tier can be re-folded at the end of the sync.
diff --git a/tests/integration/cycle-flow-opens-cycle.test.ts b/tests/integration/cycle-flow-opens-cycle.test.ts
index 5e81fda56..7a9fe7d84 100644
--- a/tests/integration/cycle-flow-opens-cycle.test.ts
+++ b/tests/integration/cycle-flow-opens-cycle.test.ts
@@ -70,6 +70,14 @@ beforeEach(async () => {
       username: "cycle-flow",
       email: "cycle-flow@example.test",
       gender: "FEMALE",
+      // The suite runs under TZ=UTC and computes its relative day keys with
+      // local Date arithmetic, i.e. in UTC. The route resolves "today" in the
+      // USER's zone and falls back to Europe/Berlin when none is set - one
+      // hour past 22:00 UTC the two clocks disagree about the date and every
+      // day-of-cycle assertion is off by one. Pinning the fixture zone to UTC
+      // makes the test's clock and the route's clock the same clock at any
+      // hour of the day.
+      timezone: "UTC",
     },
   });
   await loginAs(USER_ID);
diff --git a/tests/integration/cycle-routes.test.ts b/tests/integration/cycle-routes.test.ts
index 8dc05e92b..d75c8822f 100644
--- a/tests/integration/cycle-routes.test.ts
+++ b/tests/integration/cycle-routes.test.ts
@@ -69,6 +69,14 @@ beforeEach(async () => {
       username: "cycle-female",
       email: "cycle-female@example.test",
       gender: "FEMALE",
+      // The suite runs under TZ=UTC and computes its relative day keys with
+      // local Date arithmetic, i.e. in UTC. The route resolves "today" in the
+      // USER's zone and falls back to Europe/Berlin when none is set - one
+      // hour past 22:00 UTC the two clocks disagree about the date and every
+      // day-of-cycle assertion is off by one. Pinning the fixture zone to UTC
+      // makes the test's clock and the route's clock the same clock at any
+      // hour of the day.
+      timezone: "UTC",
     },
   });
   await prisma.user.create({
@@ -77,6 +85,7 @@ beforeEach(async () => {
       username: "cycle-male",
       email: "cycle-male@example.test",
       gender: "MALE",
+      timezone: "UTC",
     },
   });
 });
diff --git a/tests/integration/lab-source-reference-range.test.ts b/tests/integration/lab-source-reference-range.test.ts
new file mode 100644
index 000000000..34c20123a
--- /dev/null
+++ b/tests/integration/lab-source-reference-range.test.ts
@@ -0,0 +1,298 @@
+/**
+ * The whole path a printed reference range travels, against a real Postgres.
+ *
+ * The failure this pins is a two-ended one: until now the document reading
+ * pulled the value off a lab report and dropped the range printed beside it,
+ * and every end of that pipe looked healthy on its own. So the assertions here
+ * follow ONE range through the real assembly rather than checking each end in
+ * isolation:
+ *
+ *   extract  → the staged fact carries the printed string
+ *   commit   → the written row carries the derived bounds AND the string
+ *   read     → the API DTO serves both windows and says which is in force
+ *   verdict  → the reading is judged against the REPORT's window, not the
+ *              catalog band — the case where the two disagree is the point
+ *   report   → the doctor-report payload and the FHIR bundle agree with it
+ *
+ * The catalog band is deliberately set so that the same number reads
+ * "in-range" against the report and "above" against the catalog. A test whose
+ * two windows agree cannot tell whether the precedence rule is wired at all.
+ */
+import { NextRequest } from "next/server";
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+import { cookieJar } from "./mock-next-headers";
+import { getPrismaClient, truncateAllTables } from "./setup";
+
+const USER_ID = "user-lab-source-range";
+
+vi.mock("next/headers", async () => {
+  const { cookieJar, headerJar } = await import("./mock-next-headers");
+  return {
+    headers: vi.fn(async () => ({
+      get: (name: string) => headerJar.get(name.toLowerCase()) ?? null,
+    })),
+    cookies: vi.fn(async () => ({
+      get: (name: string) => {
+        const value = cookieJar.get(name);
+        return value ? { name, value } : undefined;
+      },
+      set: (name: string, value: string) => {
+        cookieJar.set(name, value);
+      },
+      delete: (name: string) => {
+        cookieJar.delete(name);
+      },
+    })),
+  };
+});
+
+vi.mock("@/lib/db-compat", () => ({
+  ensureDbCompatibility: vi.fn().mockResolvedValue(undefined),
+}));
+
+beforeEach(async () => {
+  await truncateAllTables(getPrismaClient());
+  cookieJar.clear();
+  const prisma = getPrismaClient();
+  await prisma.user.create({
+    data: {
+      id: USER_ID,
+      username: "lab-source-range",
+      email: "lab-source-range@example.test",
+    },
+  });
+  const session = await prisma.session.create({
+    data: { userId: USER_ID, expiresAt: new Date(Date.now() + 3_600_000) },
+  });
+  cookieJar.set("healthlog_session", session.id);
+});
+
+/** The catalog band the marker carries. 5.2 sits ABOVE this window. */
+const CATALOG = { lowerBound: 3.5, upperBound: 5.0 };
+/** The window the report printed. 5.2 sits INSIDE this one. */
+const PRINTED = "3,9 - 5,4";
+const VALUE = 5.2;
+
+async function seedMarker() {
+  return getPrismaClient().biomarker.create({
+    data: { userId: USER_ID, name: "Kalium", unit: "mmol/L", ...CATALOG },
+  });
+}
+
+function postReq(body: unknown): NextRequest {
+  return new NextRequest("http://localhost/api/labs", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+async function readDto(analyte = "Kalium") {
+  const { GET } = await import("@/app/api/labs/route");
+  const res = await GET(
+    new NextRequest(`http://localhost/api/labs?analyte=${analyte}`),
+  );
+  expect(res.status).toBe(200);
+  const body = await res.json();
+  return body.data.results[0];
+}
+
+describe("a printed reference range, end to end", () => {
+  it("survives the document path onto the row and governs its verdict", async () => {
+    const prisma = getPrismaClient();
+    const marker = await seedMarker();
+
+    // The document path, through the REAL commit helper the confirm route
+    // calls. The fact carries what a report prints: a value, a unit, and a
+    // window stated in German notation beside it.
+    const { commitApprovedFact } = await import("@/lib/documents/commit");
+    const { encryptFactData, encryptFactProvenance } =
+      await import("@/lib/documents/store");
+    const doc = await prisma.inboundDocument.create({
+      data: {
+        userId: USER_ID,
+        filename: "befund.pdf",
+        mimeType: "application/pdf",
+        byteSize: 1024,
+        contentEncrypted: Buffer.from("stand-in for the stored bytes"),
+        status: "EXTRACTED",
+      },
+    });
+    const fact = await prisma.extractedFact.create({
+      data: {
+        documentId: doc.id,
+        userId: USER_ID,
+        factType: "OBSERVATION",
+        status: "APPROVED",
+        confidence: 0.9,
+        needsReview: false,
+        dataEncrypted: encryptFactData({
+          label: "Kalium",
+          code: null,
+          codeSystem: null,
+          value: VALUE,
+          valueText: null,
+          unit: "mmol/L",
+          referenceLow: null,
+          referenceHigh: null,
+          referenceText: PRINTED,
+          effectiveDate: "2026-07-01",
+        }),
+        provenanceEncrypted: encryptFactProvenance({
+          sourceText: "Kalium 5,2 mmol/l 3,9 - 5,4",
+          anchored: true,
+          sourceOffset: 0,
+          page: 0,
+          confidence: 0.9,
+        }),
+      },
+    });
+
+    const ref = await commitApprovedFact(USER_ID, fact);
+    expect(ref.recordType).toBe("labResult");
+
+    // The row carries BOTH readings of the printed window: the bounds derived
+    // from it and the string itself.
+    const row = await prisma.labResult.findUniqueOrThrow({
+      where: { id: ref.recordId },
+    });
+    expect(row.sourceReferenceLow).toBe(3.9);
+    expect(row.sourceReferenceHigh).toBe(5.4);
+    expect(row.sourceReferenceText).toBe(PRINTED);
+    // The catalog stamp is untouched — the marker already existed, so the
+    // document's window did not rewrite the user's own band.
+    expect(row.referenceLow).toBe(CATALOG.lowerBound);
+    expect(row.referenceHigh).toBe(CATALOG.upperBound);
+    const markerAfter = await prisma.biomarker.findUniqueOrThrow({
+      where: { id: marker.id },
+    });
+    expect(markerAfter.lowerBound).toBe(CATALOG.lowerBound);
+    expect(markerAfter.upperBound).toBe(CATALOG.upperBound);
+
+    // The read side serves both windows, names the winner, and flags that the
+    // two disagree.
+    const dto = await readDto();
+    expect(dto).toMatchObject({
+      value: VALUE,
+      referenceLow: 3.9,
+      referenceHigh: 5.4,
+      catalogReferenceLow: CATALOG.lowerBound,
+      catalogReferenceHigh: CATALOG.upperBound,
+      sourceReferenceLow: 3.9,
+      sourceReferenceHigh: 5.4,
+      sourceReferenceText: PRINTED,
+      referenceOrigin: "source",
+      referenceDivergesFromCatalog: true,
+    });
+
+    // The verdict is the point. Against the catalog band 5.2 is above range;
+    // against the window the lab printed it is inside it, and the lab's window
+    // is the one the physician read the value against.
+    expect(dto.rangeStatus).toBe("in-range");
+
+    // The doctor report reads the same window, and prints the report's own
+    // string rather than a reformatted version of it.
+    const { loadLabResults } =
+      await import("@/lib/doctor-report/clinical-records");
+    const labs = await loadLabResults(
+      USER_ID,
+      new Date("2026-01-01T00:00:00.000Z"),
+      new Date("2026-12-31T23:59:59.000Z"),
+    );
+    expect(labs?.[0]).toMatchObject({
+      referenceLow: 3.9,
+      referenceHigh: 5.4,
+      catalogReferenceLow: CATALOG.lowerBound,
+      catalogReferenceHigh: CATALOG.upperBound,
+      sourceReferenceText: PRINTED,
+      referenceOrigin: "source",
+      referenceDivergesFromCatalog: true,
+    });
+
+    // FHIR exports the same window — a receiver that trusts referenceRange
+    // must not be handed the catalog band while the app shows another.
+    const { labObservations } = await import("@/lib/fhir/resources/labs");
+    let seq = 0;
+    const observations = labObservations(
+      { labResults: labs } as Parameters<typeof labObservations>[0],
+      () => `obs-${++seq}`,
+    );
+    expect(observations[0].referenceRange?.[0]).toMatchObject({
+      low: { value: 3.9 },
+      high: { value: 5.4 },
+      text: PRINTED,
+    });
+  });
+
+  it("keeps a window it cannot read as text and leaves the catalog in force", async () => {
+    const prisma = getPrismaClient();
+    await seedMarker();
+
+    const { POST } = await import("@/app/api/labs/route");
+    const marker = await prisma.biomarker.findFirstOrThrow({
+      where: { userId: USER_ID },
+    });
+    const res = await POST(
+      postReq({
+        biomarkerId: marker.id,
+        value: VALUE,
+        sourceReferenceText: "siehe Befund",
+        takenAt: "2026-07-02T08:00:00.000Z",
+      }),
+    );
+    expect(res.status).toBe(201);
+
+    const row = await prisma.labResult.findFirstOrThrow({
+      where: { userId: USER_ID },
+    });
+    // The string is on the record — absence would be the old failure, and a
+    // fabricated bound would be worse than either.
+    expect(row.sourceReferenceText).toBe("siehe Befund");
+    expect(row.sourceReferenceLow).toBeNull();
+    expect(row.sourceReferenceHigh).toBeNull();
+
+    const dto = await readDto();
+    expect(dto).toMatchObject({
+      sourceReferenceText: "siehe Befund",
+      referenceOrigin: "catalog",
+      referenceDivergesFromCatalog: false,
+      referenceLow: CATALOG.lowerBound,
+      referenceHigh: CATALOG.upperBound,
+    });
+    // No derivable window means the catalog stays the net, so the catalog's
+    // verdict stands.
+    expect(dto.rangeStatus).toBe("above");
+  });
+
+  it("carries the window through a backup round trip", async () => {
+    const prisma = getPrismaClient();
+    const marker = await seedMarker();
+    await prisma.labResult.create({
+      data: {
+        userId: USER_ID,
+        biomarkerId: marker.id,
+        analyte: "Kalium",
+        unit: "mmol/L",
+        value: VALUE,
+        referenceLow: CATALOG.lowerBound,
+        referenceHigh: CATALOG.upperBound,
+        sourceReferenceLow: 3.9,
+        sourceReferenceHigh: 5.4,
+        sourceReferenceText: PRINTED,
+        takenAt: new Date("2026-07-01T08:00:00.000Z"),
+      },
+    });
+
+    const { buildRecordsBackupSection } =
+      await import("@/lib/export/records-backup");
+    const backup = await buildRecordsBackupSection(prisma, USER_ID, {
+      purpose: "disaster-recovery",
+    });
+    expect(backup.labResults[0]).toMatchObject({
+      sourceReferenceLow: 3.9,
+      sourceReferenceHigh: 5.4,
+      sourceReferenceText: PRINTED,
+    });
+  });
+});