diff --git a/src/__tests__/baselines/source-file-lines.json b/src/__tests__/baselines/source-file-lines.json
index 1f4e342a1..936e877ea 100644
--- a/src/__tests__/baselines/source-file-lines.json
+++ b/src/__tests__/baselines/source-file-lines.json
@@ -1,7 +1,7 @@
 {
   "$comment": "Production files over 800 lines and their length. Maintained by src/__tests__/source-size-ratchet.test.ts.",
   "count": 89,
-  "total": 99600,
+  "total": 99598,
   "entries": {
     "app/medications/page-client.tsx": 839,
     "components/charts/mood-chart.tsx": 1166,
@@ -72,7 +72,7 @@
     "lib/jobs/medication-intake-import.ts": 819,
     "lib/jobs/offhost-backup.ts": 1147,
     "lib/jobs/reaction-line.ts": 824,
-    "lib/jobs/reminder/medication-reminder-check.ts": 818,
+    "lib/jobs/reminder/medication-reminder-check.ts": 816,
     "lib/managed-profiles/handover.ts": 986,
     "lib/mcp/record-search.ts": 1467,
     "lib/mcp/rich-reads.ts": 1467,
diff --git a/src/__tests__/baselines/source-function-lines.json b/src/__tests__/baselines/source-function-lines.json
index 965c9159f..b568f3ee6 100644
--- a/src/__tests__/baselines/source-function-lines.json
+++ b/src/__tests__/baselines/source-function-lines.json
@@ -1,7 +1,7 @@
 {
   "$comment": "Production functions over 200 lines, keyed \"file :: name\", and their length. Maintained by src/__tests__/source-size-ratchet.test.ts.",
   "count": 354,
-  "total": 114417,
+  "total": 114410,
   "entries": {
     "app/achievements/page.tsx :: AchievementsPage": 206,
     "app/api/admin/backups/upload/route.ts :: apiHandler(arg)": 314,
@@ -319,8 +319,8 @@
     "lib/jobs/medication-low-stock.ts :: runMedicationLowStockTick": 286,
     "lib/jobs/oura-backfill.ts :: runOuraBackfillForUser": 236,
     "lib/jobs/reaction-line.ts :: runReactionLine": 337,
-    "lib/jobs/reminder/medication-reminder-check.ts :: handleReminderCheck": 619,
-    "lib/jobs/reminder/medication-reminder-check.ts :: handleReminderCheck > withBackgroundEvent(arg)": 614,
+    "lib/jobs/reminder/medication-reminder-check.ts :: handleReminderCheck": 616,
+    "lib/jobs/reminder/medication-reminder-check.ts :: handleReminderCheck > withBackgroundEvent(arg)": 611,
     "lib/jobs/workout-insight-generate.ts :: runWorkoutInsightGenerate": 324,
     "lib/labs/biomarker-merge.ts :: runMerge": 254,
     "lib/labs/ocr-extract.ts :: runOcrExtraction": 207,
@@ -337,7 +337,7 @@
     "lib/measurements/import-apple-health-export.ts :: streamParseExportXml > (anonymous) #2": 323,
     "lib/medications/efficacy/build-efficacy.ts :: buildMedicationEfficacy": 268,
     "lib/medications/intake-slot-dedup.ts :: dedupeUserIntakeSlots": 321,
-    "lib/medications/list-read.ts :: buildMedicationsList": 310,
+    "lib/medications/list-read.ts :: buildMedicationsList": 309,
     "lib/medications/scheduling/dose-history.ts :: reconstructDoseHistory": 218,
     "lib/multipart/stream-to-disk.ts :: streamMultipartToDisk": 272,
     "lib/notifications/dispatcher.ts :: dispatchNotification": 378,
diff --git a/src/__tests__/baselines/version-stamp-comments.json b/src/__tests__/baselines/version-stamp-comments.json
index de6f472fb..33e262ea2 100644
--- a/src/__tests__/baselines/version-stamp-comments.json
+++ b/src/__tests__/baselines/version-stamp-comments.json
@@ -1,7 +1,7 @@
 {
   "$comment": "Comment lines that open with a release version, per file under src/. Maintained by src/__tests__/version-stamp-ratchet.test.ts.",
   "count": 2897,
-  "total": 9290,
+  "total": 9285,
   "entries": {
     "__tests__/account-payload-consumer-guard.test.ts": 2,
     "__tests__/acting-account-boundary-guard.test.ts": 7,
@@ -2357,7 +2357,7 @@
     "lib/jobs/reminder/google-health-sync.ts": 1,
     "lib/jobs/reminder/insights-handlers.ts": 3,
     "lib/jobs/reminder/medication-maintenance.ts": 3,
-    "lib/jobs/reminder/medication-reminder-check.ts": 13,
+    "lib/jobs/reminder/medication-reminder-check.ts": 12,
     "lib/jobs/reminder/mood-cycle-checks.ts": 3,
     "lib/jobs/reminder/ops-handlers.ts": 3,
     "lib/jobs/reminder/oura-sync.ts": 1,
@@ -2506,7 +2506,7 @@
     "lib/medications/injection-site-write.ts": 1,
     "lib/medications/injection-sites.ts": 6,
     "lib/medications/intake-actionable.ts": 1,
-    "lib/medications/intake-slot-dedup.ts": 18,
+    "lib/medications/intake-slot-dedup.ts": 17,
     "lib/medications/intake-tracking.ts": 1,
     "lib/medications/inventory/__tests__/consumption.test.ts": 1,
     "lib/medications/inventory/__tests__/summary.test.ts": 2,
@@ -2515,7 +2515,7 @@
     "lib/medications/inventory/state-machine.ts": 2,
     "lib/medications/inventory/summary.ts": 4,
     "lib/medications/lifecycle.ts": 3,
-    "lib/medications/list-read.ts": 26,
+    "lib/medications/list-read.ts": 23,
     "lib/medications/med-target-map.ts": 1,
     "lib/medications/medication-order.ts": 1,
     "lib/medications/outstanding-doses.ts": 2,
diff --git a/src/__tests__/medication-read-order-guard.test.ts b/src/__tests__/medication-read-order-guard.test.ts
new file mode 100644
index 000000000..32bd34331
--- /dev/null
+++ b/src/__tests__/medication-read-order-guard.test.ts
@@ -0,0 +1,139 @@
+/**
+ * Every medication and intake read orders its ties.
+ *
+ * Postgres returns rows that tie on an `ORDER BY` in no particular order, and
+ * not the same one twice. The medication reads ordered by columns two rows
+ * share all the time: a schedule list with no order at all, medications by
+ * `createdAt` (one import writes many in a millisecond), intakes by
+ * `scheduledFor` (a twice-daily medication puts every morning dose on the same
+ * instant), "the latest intake" by `takenAt`. A client then read the same
+ * account in a different order from one request to the next, and a "latest"
+ * lookup picked either of two rows. The parity suite saw it as `<id:N>`
+ * labels swapping under a loaded run.
+ *
+ * So every `findMany` / `findFirst` on a medication table, its nested
+ * includes too, states an order that ends on a unique key, and a medication's
+ * schedules are never included unordered (`MEDICATION_SCHEDULE_ORDER`). An
+ * order held in a variable is checked where it is built, and listed below.
+ */
+import { join } from "node:path";
+
+import { describe, expect, it } from "vitest";
+
+import {
+  readSourceText,
+  requireFloor,
+  stripComments,
+  walkSourceFiles,
+} from "./helpers/source-files";
+
+const SRC = join(__dirname, "..");
+
+const READ =
+  /\b(?:prisma|tx|db|client)\s*\.\s*(medication|medicationSchedule|medicationIntakeEvent|medicationScheduleRevision|medicationPauseEra|medicationCourse|medicationDoseChange|medicationInventoryItem|medicationInventoryEvent|medicationSideEffect|medicationIngredient|medicationCategoryAssignment)\s*\.\s*(findMany|findFirst|findFirstOrThrow)\s*\(/g;
+
+/** Unique keys an order may end on, beyond `id`. */
+const UNIQUE_LAST_KEYS: Record<string, string> = {
+  medicationCategoryAssignment: "medicationId",
+};
+
+/** Orders built in a variable, by file, with where the tie-breaker lives. */
+const ORDER_VARIABLES: Record<string, string> = {
+  "lib/medications/list-intake-events.ts":
+    "`orderBy` ends on `{ id: sortDir }` in both arms, built just above the read.",
+};
+
+function closing(text: string, at: number, open: string, close: string) {
+  let depth = 0;
+  for (let i = at; i < text.length; i++) {
+    if (text[i] === open) depth++;
+    else if (text[i] === close && --depth === 0) return i;
+  }
+  return -1;
+}
+
+interface Read {
+  where: string;
+  model: string;
+  orders: string[];
+  variableOrder: boolean;
+  unorderedSchedules: boolean;
+}
+
+function reads(): Read[] {
+  const out: Read[] = [];
+  const files = walkSourceFiles(SRC, { floor: 2000 }).filter(
+    (rel) => !rel.startsWith("generated/") && !rel.includes("__tests__"),
+  );
+  for (const rel of files) {
+    const text = stripComments(readSourceText(join(SRC, rel)), rel);
+    for (const match of text.matchAll(READ)) {
+      const open = match.index! + match[0].length - 1;
+      const end = closing(text, open, "(", ")");
+      const call = text.slice(open, end + 1);
+      const orders: string[] = [];
+      for (const order of call.matchAll(/orderBy\s*:\s*([[{])/g)) {
+        const start = order.index! + order[0].length - 1;
+        const bracket = order[1]!;
+        const stop = closing(call, start, bracket, bracket === "[" ? "]" : "}");
+        orders.push(call.slice(start, stop + 1).replace(/\s+/g, " "));
+      }
+      out.push({
+        where: `${rel}:${text.slice(0, match.index).split("\n").length}`,
+        model: match[1]!,
+        orders,
+        variableOrder: /\borderBy\s*(?:,|\})/.test(call),
+        unorderedSchedules: /\bschedules\s*:\s*true\b/.test(call),
+      });
+    }
+  }
+  return out;
+}
+
+const ALL = reads();
+
+/** Whether an order's last key is unique for the read's model. */
+function endsUnique(order: string, model: string): boolean {
+  const keys = [...order.matchAll(/(\w+)\s*:\s*(?:"(?:asc|desc)"|\{|\w)/g)]
+    .map((m) => m[1]!)
+    .filter((key) => key !== "sort" && key !== "nulls");
+  const last = keys.at(-1);
+  return last === "id" || last === UNIQUE_LAST_KEYS[model];
+}
+
+describe("medication reads order their ties", () => {
+  it("finds the reads it is about", () => {
+    requireFloor("medication reads", ALL, 150);
+    requireFloor(
+      "ordered medication reads",
+      ALL.filter((read) => read.orders.length > 0),
+      60,
+    );
+  });
+
+  it("ends every stated order on a unique key", () => {
+    const loose = ALL.flatMap((read) =>
+      read.orders
+        .filter((order) => !endsUnique(order, read.model))
+        .map((order) => `${read.where} ${read.model}: ${order}`),
+    );
+    expect(loose).toEqual([]);
+  });
+
+  it("never includes a medication's schedules unordered", () => {
+    expect(
+      ALL.filter((read) => read.unorderedSchedules).map((read) => read.where),
+    ).toEqual([]);
+  });
+
+  it("names every order held in a variable, and nothing else", () => {
+    const files = [
+      ...new Set(
+        ALL.filter((read) => read.variableOrder).map(
+          (read) => read.where.split(":")[0]!,
+        ),
+      ),
+    ].sort();
+    expect(files).toEqual(Object.keys(ORDER_VARIABLES).sort());
+  });
+});
diff --git a/src/app/api/__tests__/inline-schema-strictness-inventory.test.ts b/src/app/api/__tests__/inline-schema-strictness-inventory.test.ts
index 80a5dc67f..8fc5f168f 100644
--- a/src/app/api/__tests__/inline-schema-strictness-inventory.test.ts
+++ b/src/app/api/__tests__/inline-schema-strictness-inventory.test.ts
@@ -190,7 +190,6 @@ const DELIBERATELY_OPEN: Record<string, { count: number; reason: string }> = {
   //    not read would make a backup unrestorable on the version that has
   //    to restore it, which is the one job a backup has.
   // ---------------------------------------------------------------
-  "import/route.ts": { count: 3, reason: "foreign archive" },
   "medications/[id]/intake/import/route.ts": {
     count: 1,
     reason: "foreign archive",
diff --git a/src/app/api/admin/notifications/reminder-check/route.ts b/src/app/api/admin/notifications/reminder-check/route.ts
index f161051d4..736677301 100644
--- a/src/app/api/admin/notifications/reminder-check/route.ts
+++ b/src/app/api/admin/notifications/reminder-check/route.ts
@@ -11,6 +11,7 @@ import { getUserTodayBounds, getDayOfWeekInTz } from "@/lib/tz/local-day";
 import { sendsMedicationReminders } from "@/lib/medications/auto-mark-taken";
 import { TRACKED_INTAKE_WHERE } from "@/lib/medications/intake-tracking";
 import { DEFAULT_TIMEZONE } from "@/lib/tz/format";
+import { MEDICATION_SCHEDULE_ORDER } from "@/lib/medications/read-order";
 
 export const dynamic = "force-dynamic";
 
@@ -109,7 +110,7 @@ export const POST = apiHandler(async (request: NextRequest) => {
       ...(scopedUserId ? { userId: scopedUserId } : {}),
     },
     include: {
-      schedules: true,
+      schedules: { orderBy: MEDICATION_SCHEDULE_ORDER },
       user: { select: { id: true, username: true, timezone: true } },
     },
   });
diff --git a/src/app/api/export/medications/route.ts b/src/app/api/export/medications/route.ts
index 8ec77cd18..05c0dd6ca 100644
--- a/src/app/api/export/medications/route.ts
+++ b/src/app/api/export/medications/route.ts
@@ -76,7 +76,7 @@ export const GET = apiHandler(async (request: NextRequest) => {
           },
         },
       },
-      orderBy: { createdAt: "desc" },
+      orderBy: [{ createdAt: "desc" }, { id: "desc" }],
     }),
     resolveUserTimezone(user.id),
   ]);
@@ -114,7 +114,7 @@ export const GET = apiHandler(async (request: NextRequest) => {
     const events = await prisma.medicationIntakeEvent.findMany({
       where,
       include: { medication: { select: { name: true } } },
-      orderBy: { scheduledFor: "desc" },
+      orderBy: [{ scheduledFor: "desc" }, { id: "desc" }],
     });
     intakeCount = events.length;
     sections.push("# Intake history");
diff --git a/src/app/api/export/route.ts b/src/app/api/export/route.ts
index 4020fc835..f3c6c89ec 100644
--- a/src/app/api/export/route.ts
+++ b/src/app/api/export/route.ts
@@ -19,6 +19,7 @@ import {
 import { resolveUserTimezone } from "@/lib/tz/resolver";
 import { loadUserSourcePriority } from "@/lib/rollups/measurement-read";
 import { NextRequest, NextResponse } from "next/server";
+import { MEDICATION_SCHEDULE_ORDER } from "@/lib/medications/read-order";
 
 /**
  * Export user data.
@@ -122,8 +123,8 @@ export const GET = apiHandler(async (request: NextRequest) => {
   if (type === "medications" || type === "all") {
     const medications = await prisma.medication.findMany({
       where: { userId },
-      include: { schedules: true },
-      orderBy: { createdAt: "desc" },
+      include: { schedules: { orderBy: MEDICATION_SCHEDULE_ORDER } },
+      orderBy: [{ createdAt: "desc" }, { id: "desc" }],
     });
     data.medications =
       format === "csv"
@@ -135,7 +136,7 @@ export const GET = apiHandler(async (request: NextRequest) => {
     const events = await prisma.medicationIntakeEvent.findMany({
       where: { userId, deletedAt: null },
       include: { medication: { select: { name: true } } },
-      orderBy: { scheduledFor: "desc" },
+      orderBy: [{ scheduledFor: "desc" }, { id: "desc" }],
     });
     data.intakeEvents =
       format === "csv"
diff --git a/src/app/api/insights/cards/route.ts b/src/app/api/insights/cards/route.ts
index 7d67ae7c4..04779c3ba 100644
--- a/src/app/api/insights/cards/route.ts
+++ b/src/app/api/insights/cards/route.ts
@@ -116,7 +116,7 @@ export const GET = apiHandler(async () => {
           // per-dose windows reach the engine like every other surface.
           schedules: { select: SCHEDULE_COMPLIANCE_SELECT },
           // v1.16.3 — archived schedule eras for era-aware expected counts.
-          scheduleRevisions: { orderBy: { validFrom: "asc" } },
+          scheduleRevisions: { orderBy: [{ validFrom: "asc" }, { id: "asc" }] },
           // v1.25 — pause eras so paused days drop out of the denominator.
           pauseEras: { select: { pausedAt: true, resumedAt: true } },
           // v1.40 (#1024) — the courses, so a gap between two expects nothing.
@@ -207,7 +207,7 @@ export const GET = apiHandler(async () => {
         // intakes outside the 30-day rate window.
         scheduledFor: { gte: ninetyDaysAgo },
       },
-      orderBy: { scheduledFor: "desc" },
+      orderBy: [{ scheduledFor: "desc" }, { id: "desc" }],
       select: {
         medicationId: true,
         takenAt: true,
diff --git a/src/app/api/insights/glp1-timeline/route.ts b/src/app/api/insights/glp1-timeline/route.ts
index 580e8c104..3419a917a 100644
--- a/src/app/api/insights/glp1-timeline/route.ts
+++ b/src/app/api/insights/glp1-timeline/route.ts
@@ -48,10 +48,10 @@ export const GET = apiHandler(async (request: NextRequest) => {
   const meds = await prisma.medication.findMany({
     where: { userId: user.id, treatmentClass: "GLP1" },
     include: {
-      doseChanges: { orderBy: { effectiveFrom: "asc" } },
+      doseChanges: { orderBy: [{ effectiveFrom: "asc" }, { id: "asc" }] },
       intakeEvents: {
         where: { takenAt: { not: null } },
-        orderBy: { takenAt: "desc" },
+        orderBy: [{ takenAt: "desc" }, { id: "desc" }],
         take: 50,
       },
       // v1.16.10 divergence note: the stock READOUTS (glp1 details
@@ -63,7 +63,10 @@ export const GET = apiHandler(async (request: NextRequest) => {
       // only grows through the legacy `POST /api/medications/[id]/glp1`
       // inventory branch, so timelines on item-tracked medications show
       // no new inventory entries.
-      inventoryEvents: { orderBy: { occurredAt: "desc" }, take: 20 },
+      inventoryEvents: {
+        orderBy: [{ occurredAt: "desc" }, { id: "desc" }],
+        take: 20,
+      },
     },
   });
 
diff --git a/src/app/api/medications/[id]/__tests__/route.test.ts b/src/app/api/medications/[id]/__tests__/route.test.ts
index a1791b827..39b43f603 100644
--- a/src/app/api/medications/[id]/__tests__/route.test.ts
+++ b/src/app/api/medications/[id]/__tests__/route.test.ts
@@ -633,7 +633,7 @@ describe("PUT /api/medications/[id] — primary-schedule grace bridge", () => {
     expect(res.status).toBe(200);
     expect(prisma.medicationSchedule.findFirst).toHaveBeenCalledWith({
       where: { medicationId: "m1" },
-      orderBy: { windowStart: "asc" },
+      orderBy: [{ windowStart: "asc" }, { id: "asc" }],
       select: { id: true },
     });
     expect(prisma.medicationSchedule.update).toHaveBeenCalledWith({
diff --git a/src/app/api/medications/[id]/cadence/route.ts b/src/app/api/medications/[id]/cadence/route.ts
index 652623365..a54907ec5 100644
--- a/src/app/api/medications/[id]/cadence/route.ts
+++ b/src/app/api/medications/[id]/cadence/route.ts
@@ -108,7 +108,7 @@ export const GET = apiHandler(
         // chips agree with the % + the history on a "zugeordnet" dose.
         attributionSource: true,
       },
-      orderBy: { scheduledFor: "asc" },
+      orderBy: [{ scheduledFor: "asc" }, { id: "asc" }],
     });
 
     // The cadence-anchor is the medication's createdAt for stable
diff --git a/src/app/api/medications/[id]/dose-history/route.ts b/src/app/api/medications/[id]/dose-history/route.ts
index acb1e411b..61b323b4d 100644
--- a/src/app/api/medications/[id]/dose-history/route.ts
+++ b/src/app/api/medications/[id]/dose-history/route.ts
@@ -166,7 +166,7 @@ export const GET = apiHandler(
 
     const events = await prisma.medicationIntakeEvent.findMany({
       where: { medicationId: id, userId: user.id, deletedAt: null },
-      orderBy: { scheduledFor: "desc" },
+      orderBy: [{ scheduledFor: "desc" }, { id: "desc" }],
       select: {
         id: true,
         scheduledFor: true,
diff --git a/src/app/api/medications/[id]/inventory/route.ts b/src/app/api/medications/[id]/inventory/route.ts
index 79836f72e..370845fed 100644
--- a/src/app/api/medications/[id]/inventory/route.ts
+++ b/src/app/api/medications/[id]/inventory/route.ts
@@ -50,7 +50,12 @@ export const GET = apiHandler(
     const [items, medication] = await Promise.all([
       prisma.medicationInventoryItem.findMany({
         where: { userId: user.id, medicationId: id },
-        orderBy: [{ state: "asc" }, { expiresAt: "asc" }, { createdAt: "asc" }],
+        orderBy: [
+          { state: "asc" },
+          { expiresAt: "asc" },
+          { createdAt: "asc" },
+          { id: "asc" },
+        ],
       }),
       prisma.medication.findUnique({
         where: { id },
diff --git a/src/app/api/medications/[id]/schedule-revisions/route.ts b/src/app/api/medications/[id]/schedule-revisions/route.ts
index 18be90e7a..9d5b3c7f8 100644
--- a/src/app/api/medications/[id]/schedule-revisions/route.ts
+++ b/src/app/api/medications/[id]/schedule-revisions/route.ts
@@ -86,7 +86,7 @@ export const GET = apiHandler(
       // Superseded rows are audit records behind a correction — the
       // timeline shows the corrected state, like every era consumer.
       where: { medicationId: id, supersededByRevisionId: null },
-      orderBy: { validFrom: "desc" },
+      orderBy: [{ validFrom: "desc" }, { id: "desc" }],
       select: {
         id: true,
         validFrom: true,
diff --git a/src/app/api/medications/compliance/route.ts b/src/app/api/medications/compliance/route.ts
index e2698eda4..04d578e7b 100644
--- a/src/app/api/medications/compliance/route.ts
+++ b/src/app/api/medications/compliance/route.ts
@@ -21,6 +21,7 @@ import { cachedSwr, caches, type ServerCache } from "@/lib/cache/server-cache";
 import { checkRateLimit } from "@/lib/rate-limit";
 import { TRACKED_INTAKE_WHERE } from "@/lib/medications/intake-tracking";
 import { DEFAULT_TIMEZONE } from "@/lib/tz/format";
+import { MEDICATION_SCHEDULE_ORDER } from "@/lib/medications/read-order";
 
 /**
  * Batched card-compliance read: one round trip for every medication the
@@ -82,15 +83,15 @@ export const GET = apiHandler(async (request: Request) => {
     // of rates, and an empty expected set must not read as 0% or 100%.
     where: { userId: user.id, asNeeded: false, ...TRACKED_INTAKE_WHERE },
     include: {
-      schedules: true,
+      schedules: { orderBy: MEDICATION_SCHEDULE_ORDER },
       // v1.16.3 — archived schedule eras for era-aware compliance.
-      scheduleRevisions: { orderBy: { validFrom: "asc" } },
+      scheduleRevisions: { orderBy: [{ validFrom: "asc" }, { id: "asc" }] },
       // v1.25 — pause eras so paused days drop out of the denominator.
       pauseEras: { select: { pausedAt: true, resumedAt: true } },
       // v1.40 (#1024) — the courses, so a gap between two expects nothing.
       courses: COURSES_COMPLIANCE_SELECT,
     },
-    orderBy: { createdAt: "desc" },
+    orderBy: [{ createdAt: "desc" }, { id: "desc" }],
   });
 
   // Bounded fan-out: each cold cell costs one bounded intake read + one
diff --git a/src/app/api/sync/state/route.ts b/src/app/api/sync/state/route.ts
index 4d4083640..713f52e74 100644
--- a/src/app/api/sync/state/route.ts
+++ b/src/app/api/sync/state/route.ts
@@ -83,7 +83,7 @@ export const GET = apiHandler(async (_request: NextRequest) => {
     }),
     prisma.medicationIntakeEvent.findFirst({
       where: { userId: user.id, deletedAt: null },
-      orderBy: { updatedAt: "desc" },
+      orderBy: [{ updatedAt: "desc" }, { id: "desc" }],
       select: { updatedAt: true },
     }),
     prisma.medicationIntakeEvent.count({
diff --git a/src/lib/ai/coach/glp1-snapshot.ts b/src/lib/ai/coach/glp1-snapshot.ts
index 0953708f4..6028f7644 100644
--- a/src/lib/ai/coach/glp1-snapshot.ts
+++ b/src/lib/ai/coach/glp1-snapshot.ts
@@ -38,6 +38,7 @@ import {
   userDayKey,
   weekdayOfDateKey,
 } from "@/lib/tz/format";
+import { MEDICATION_SCHEDULE_ORDER } from "@/lib/medications/read-order";
 
 /**
  * Recommended generic name for the canonical GLP-1 drug brand. The Coach
@@ -246,18 +247,18 @@ export async function buildGlp1SnapshotBlock(
       active: true,
     },
     include: {
-      schedules: true,
-      doseChanges: { orderBy: { effectiveFrom: "asc" } },
+      schedules: { orderBy: MEDICATION_SCHEDULE_ORDER },
+      doseChanges: { orderBy: [{ effectiveFrom: "asc" }, { id: "asc" }] },
       // v1.16.10 — pen inventory reads the per-item entities (the rows
       // the intake consumption hook moves). The legacy event ledger
       // stays as a READ fallback for ledger-only accounts: when a
       // medication has zero items, the running-sum numbers surface so
       // the Coach still knows the pen count.
-      inventoryItems: { orderBy: { createdAt: "asc" } },
-      inventoryEvents: { orderBy: { occurredAt: "asc" } },
+      inventoryItems: { orderBy: [{ createdAt: "asc" }, { id: "asc" }] },
+      inventoryEvents: { orderBy: [{ occurredAt: "asc" }, { id: "asc" }] },
       intakeEvents: {
         where: { takenAt: floor ? { not: null, gte: floor } : { not: null } },
-        orderBy: { takenAt: "desc" },
+        orderBy: [{ takenAt: "desc" }, { id: "desc" }],
         take: 1,
         select: {
           takenAt: true,
diff --git a/src/lib/ai/coach/snapshot.ts b/src/lib/ai/coach/snapshot.ts
index 57ca5fd1a..2bc7a4abc 100644
--- a/src/lib/ai/coach/snapshot.ts
+++ b/src/lib/ai/coach/snapshot.ts
@@ -517,7 +517,7 @@ async function buildCoachSnapshotImpl(
           createdAt: true,
           schedules: { select: SCHEDULE_COMPLIANCE_SELECT },
           scheduleRevisions: {
-            orderBy: { validFrom: "asc" },
+            orderBy: [{ validFrom: "asc" }, { id: "asc" }],
             select: {
               id: true,
               validFrom: true,
@@ -533,7 +533,7 @@ async function buildCoachSnapshotImpl(
           intakeEvents: {
             // Tombstoned intake rows must never reach the Coach snapshot.
             where: { deletedAt: null, scheduledFor: { gte: cutoff } },
-            orderBy: { scheduledFor: "asc" },
+            orderBy: [{ scheduledFor: "asc" }, { id: "asc" }],
             select: {
               scheduledFor: true,
               takenAt: true,
diff --git a/src/lib/analytics/schedule-anchored-compliance.ts b/src/lib/analytics/schedule-anchored-compliance.ts
index bec832e63..afa4bf568 100644
--- a/src/lib/analytics/schedule-anchored-compliance.ts
+++ b/src/lib/analytics/schedule-anchored-compliance.ts
@@ -68,7 +68,7 @@ export async function buildScheduleAnchoredComplianceBuckets(
       // reaches this surface the moment it joins SCHEDULE_COMPLIANCE_SELECT.
       schedules: { select: SCHEDULE_COMPLIANCE_SELECT },
       // v1.16.3 — archived schedule eras for era-aware expected counts.
-      scheduleRevisions: { orderBy: { validFrom: "asc" } },
+      scheduleRevisions: { orderBy: [{ validFrom: "asc" }, { id: "asc" }] },
       // v1.25 — pause eras so paused days drop out of the denominator.
       pauseEras: { select: { pausedAt: true, resumedAt: true } },
       // v1.40 (#1024) — the courses, so a gap between two expects nothing.
diff --git a/src/lib/dashboard/meds-today.ts b/src/lib/dashboard/meds-today.ts
index 24382dfe5..f8b9d54af 100644
--- a/src/lib/dashboard/meds-today.ts
+++ b/src/lib/dashboard/meds-today.ts
@@ -49,6 +49,7 @@ import {
   TRACKED_INTAKE_WHERE,
 } from "@/lib/medications/intake-tracking";
 import { liveEraStartsByMedication } from "@/lib/medications/scheduling/live-era";
+import { MEDICATION_SCHEDULE_ORDER } from "@/lib/medications/read-order";
 
 export interface MedsTodayDueCandidate {
   medicationId: string;
@@ -138,8 +139,8 @@ export async function buildMedsTodayBlock(
       // place on the doses card: not counted, never the next due dose.
       prisma.medication.findMany({
         where: { userId, active: true, ...TRACKED_INTAKE_WHERE },
-        include: { schedules: true },
-        orderBy: { createdAt: "desc" },
+        include: { schedules: { orderBy: MEDICATION_SCHEDULE_ORDER } },
+        orderBy: [{ createdAt: "desc" }, { id: "desc" }],
       }),
       prisma.medicationIntakeEvent.findMany({
         where: {
diff --git a/src/lib/day/records.ts b/src/lib/day/records.ts
index 35138b89d..31be1a0bb 100644
--- a/src/lib/day/records.ts
+++ b/src/lib/day/records.ts
@@ -202,7 +202,7 @@ async function medicationsPart(frame: DayFrame): Promise<SectionPart> {
           doseTaken: true,
           medication: { select: { name: true, dose: true } },
         },
-        orderBy: { takenAt: "asc" },
+        orderBy: [{ takenAt: "asc" }, { id: "asc" }],
       }),
       prisma.medicationDoseChange.findMany({
         where: {
@@ -229,7 +229,7 @@ async function medicationsPart(frame: DayFrame): Promise<SectionPart> {
           doseValue: true,
           doseUnit: true,
         },
-        orderBy: { effectiveFrom: "desc" },
+        orderBy: [{ effectiveFrom: "desc" }, { id: "desc" }],
         distinct: ["medicationId"],
       }),
     ]);
diff --git a/src/lib/doctor-report/collect.ts b/src/lib/doctor-report/collect.ts
index 541dcd403..eb19713ef 100644
--- a/src/lib/doctor-report/collect.ts
+++ b/src/lib/doctor-report/collect.ts
@@ -322,7 +322,7 @@ export async function collectDoctorReportData(
                 select: { ...SCHEDULE_COMPLIANCE_SELECT, label: true },
               },
               scheduleRevisions: {
-                orderBy: { validFrom: "asc" },
+                orderBy: [{ validFrom: "asc" }, { id: "asc" }],
                 select: {
                   id: true,
                   validFrom: true,
@@ -336,11 +336,11 @@ export async function collectDoctorReportData(
               courses: COURSES_COMPLIANCE_SELECT,
               doseChanges: {
                 where: { effectiveFrom: { lte: end } },
-                orderBy: { effectiveFrom: "asc" },
+                orderBy: [{ effectiveFrom: "asc" }, { id: "asc" }],
               },
               intakeEvents: {
                 where: { takenAt: { not: null, lte: end } },
-                orderBy: { takenAt: "desc" },
+                orderBy: [{ takenAt: "desc" }, { id: "desc" }],
                 take: 1,
                 select: { takenAt: true, injectionSite: true },
               },
@@ -367,7 +367,7 @@ export async function collectDoctorReportData(
                 },
               },
             },
-            orderBy: { scheduledFor: "asc" },
+            orderBy: [{ scheduledFor: "asc" }, { id: "asc" }],
           })
         : Promise.resolve([]),
       // Zero DB read when the mood leaf was not chosen: the payload reflects
diff --git a/src/lib/import/json/schema.ts b/src/lib/import/json/schema.ts
index aea967780..7b33bdd1a 100644
--- a/src/lib/import/json/schema.ts
+++ b/src/lib/import/json/schema.ts
@@ -10,6 +10,11 @@
  *
  * Lives here rather than in the route because the route module may export
  * nothing but its handlers, and the guard needs the field set.
+ *
+ * The objects are deliberately not strict. A file is a foreign archive: the
+ * app's own files carry fields the import leaves out on purpose (row ids, the
+ * source, sync bookkeeping), and a strict object would refuse every one of
+ * them. An unknown key is stripped, never stored.
  */
 import { z } from "zod/v4";
 
diff --git a/src/lib/insights/blood-pressure-status.ts b/src/lib/insights/blood-pressure-status.ts
index f5e5d80bd..566e9cc3f 100644
--- a/src/lib/insights/blood-pressure-status.ts
+++ b/src/lib/insights/blood-pressure-status.ts
@@ -480,7 +480,7 @@ async function readBpMedicationContext(
     include: {
       schedules: { select: SCHEDULE_COMPLIANCE_SELECT },
       // v1.16.3 — archived schedule eras for era-aware compliance.
-      scheduleRevisions: { orderBy: { validFrom: "asc" } },
+      scheduleRevisions: { orderBy: [{ validFrom: "asc" }, { id: "asc" }] },
       // v1.25 — pause eras so paused days drop out of the denominator.
       pauseEras: { select: { pausedAt: true, resumedAt: true } },
       // v1.40 (#1024) — the courses, so a gap between two expects nothing.
@@ -521,7 +521,7 @@ async function readBpMedicationContext(
               in: bpMedications.map((medication) => medication.id),
             },
           },
-          orderBy: { scheduledFor: "asc" },
+          orderBy: [{ scheduledFor: "asc" }, { id: "asc" }],
           select: {
             medicationId: true,
             scheduledFor: true,
diff --git a/src/lib/insights/comprehensive-overview/medication-compliance.ts b/src/lib/insights/comprehensive-overview/medication-compliance.ts
index 43a4567ab..3382a6069 100644
--- a/src/lib/insights/comprehensive-overview/medication-compliance.ts
+++ b/src/lib/insights/comprehensive-overview/medication-compliance.ts
@@ -36,7 +36,7 @@ async function readScheduledMedications(userId: string) {
       // per-dose windows reach this surface like every other.
       schedules: { select: SCHEDULE_COMPLIANCE_SELECT },
       // Archived schedule eras for era-aware compliance.
-      scheduleRevisions: { orderBy: { validFrom: "asc" } },
+      scheduleRevisions: { orderBy: [{ validFrom: "asc" }, { id: "asc" }] },
       // Pause eras so paused days drop out of the denominator.
       pauseEras: { select: { pausedAt: true, resumedAt: true } },
       // The courses, so a gap between two expects nothing (#1024).
@@ -85,7 +85,7 @@ export async function readMedicationCompliance(args: {
           deletedAt: null,
           scheduledFor: { gte: since },
         },
-        orderBy: { scheduledFor: "desc" },
+        orderBy: [{ scheduledFor: "desc" }, { id: "desc" }],
       })
     : [];
 
diff --git a/src/lib/insights/correlation-channel-series.ts b/src/lib/insights/correlation-channel-series.ts
index 25f971c18..5626f2b5d 100644
--- a/src/lib/insights/correlation-channel-series.ts
+++ b/src/lib/insights/correlation-channel-series.ts
@@ -115,13 +115,13 @@ export async function fetchComplianceSeries(
     where: { userId, active: true, asNeeded: false, ...TRACKED_INTAKE_WHERE },
     include: {
       schedules: { select: SCHEDULE_COMPLIANCE_SELECT },
-      scheduleRevisions: { orderBy: { validFrom: "asc" } },
+      scheduleRevisions: { orderBy: [{ validFrom: "asc" }, { id: "asc" }] },
       // v1.25 — pause eras so paused days drop out of the denominator.
       pauseEras: { select: { pausedAt: true, resumedAt: true } },
       // v1.40 (#1024) — the courses, so a gap between two expects nothing.
       courses: COURSES_COMPLIANCE_SELECT,
     },
-    orderBy: { name: "asc" },
+    orderBy: [{ name: "asc" }, { id: "asc" }],
   });
   if (medications.length === 0) {
     return {
@@ -138,7 +138,7 @@ export async function fetchComplianceSeries(
       medicationId: { in: medications.map((med) => med.id) },
       scheduledFor: { gte: since },
     },
-    orderBy: { scheduledFor: "asc" },
+    orderBy: [{ scheduledFor: "asc" }, { id: "asc" }],
     select: {
       medicationId: true,
       scheduledFor: true,
diff --git a/src/lib/insights/features.ts b/src/lib/insights/features.ts
index 9d5bbc908..2ac921ee6 100644
--- a/src/lib/insights/features.ts
+++ b/src/lib/insights/features.ts
@@ -1667,7 +1667,7 @@ export async function extractFeatures(
     include: {
       schedules: { select: SCHEDULE_COMPLIANCE_SELECT },
       // v1.16.3 — archived schedule eras for era-aware compliance.
-      scheduleRevisions: { orderBy: { validFrom: "asc" } },
+      scheduleRevisions: { orderBy: [{ validFrom: "asc" }, { id: "asc" }] },
       // v1.25 — pause eras so paused days drop out of the denominator.
       pauseEras: { select: { pausedAt: true, resumedAt: true } },
       // v1.40 (#1024) — the courses, so a gap between two expects nothing.
@@ -1696,7 +1696,7 @@ export async function extractFeatures(
         medicationId: { in: medications.map((med) => med.id) },
         scheduledFor: { gte: ninetyDaysAgo },
       },
-      orderBy: { scheduledFor: "desc" },
+      orderBy: [{ scheduledFor: "desc" }, { id: "desc" }],
       select: {
         medicationId: true,
         takenAt: true,
diff --git a/src/lib/insights/general-status.ts b/src/lib/insights/general-status.ts
index 9612b8975..2857bcb24 100644
--- a/src/lib/insights/general-status.ts
+++ b/src/lib/insights/general-status.ts
@@ -248,7 +248,7 @@ async function readAdherenceSeries(userId: string, now: Date, userTz: string) {
       // v1.39.1 (#1033) — adherence counts tracked medications only.
       ...TRACKED_INTAKE_EVENT_WHERE,
     },
-    orderBy: { scheduledFor: "asc" },
+    orderBy: [{ scheduledFor: "asc" }, { id: "asc" }],
     select: {
       scheduledFor: true,
       takenAt: true,
diff --git a/src/lib/insights/glp1-plateau.ts b/src/lib/insights/glp1-plateau.ts
index 6f7d11bfd..6e1307e99 100644
--- a/src/lib/insights/glp1-plateau.ts
+++ b/src/lib/insights/glp1-plateau.ts
@@ -63,7 +63,10 @@ export async function detectGlp1Plateau(
   const meds = await prisma.medication.findMany({
     where: { userId, treatmentClass: "GLP1", active: true },
     include: {
-      doseChanges: { orderBy: { effectiveFrom: "desc" }, take: 1 },
+      doseChanges: {
+        orderBy: [{ effectiveFrom: "desc" }, { id: "desc" }],
+        take: 1,
+      },
     },
   });
   if (meds.length === 0) return null;
diff --git a/src/lib/insights/medication-compliance-status.ts b/src/lib/insights/medication-compliance-status.ts
index a71719ec9..f2d65ca92 100644
--- a/src/lib/insights/medication-compliance-status.ts
+++ b/src/lib/insights/medication-compliance-status.ts
@@ -286,7 +286,7 @@ async function buildMedicationComplianceSnapshot(
       medicationId: { in: medications.map((medication) => medication.id) },
       scheduledFor: { gte: rangeStart },
     },
-    orderBy: { scheduledFor: "asc" },
+    orderBy: [{ scheduledFor: "asc" }, { id: "asc" }],
     select: {
       medicationId: true,
       scheduledFor: true,
@@ -394,13 +394,13 @@ async function readComplianceMedications(userId: string) {
     include: {
       schedules: { select: SCHEDULE_COMPLIANCE_SELECT },
       // v1.16.3 — archived schedule eras for era-aware compliance.
-      scheduleRevisions: { orderBy: { validFrom: "asc" } },
+      scheduleRevisions: { orderBy: [{ validFrom: "asc" }, { id: "asc" }] },
       // v1.25 — pause eras so paused days drop out of the denominator.
       pauseEras: { select: { pausedAt: true, resumedAt: true } },
       // v1.40 (#1024) — the courses, so a gap between two expects nothing.
       courses: COURSES_COMPLIANCE_SELECT,
     },
-    orderBy: { name: "asc" },
+    orderBy: [{ name: "asc" }, { id: "asc" }],
   });
 
   // A medication with no schedule expects no dose, and `calculateCompliance`
diff --git a/src/lib/jobs/intake-auto-take.ts b/src/lib/jobs/intake-auto-take.ts
index 16265f1d2..2b7c7cc9f 100644
--- a/src/lib/jobs/intake-auto-take.ts
+++ b/src/lib/jobs/intake-auto-take.ts
@@ -269,7 +269,7 @@ export async function runIntakeAutoTakePass(
       autoMarkTakenSince: true,
       schedules: { select: SCHEDULE_SELECT },
       scheduleRevisions: {
-        orderBy: { validFrom: "asc" },
+        orderBy: [{ validFrom: "asc" }, { id: "asc" }],
         select: {
           id: true,
           validFrom: true,
@@ -423,7 +423,7 @@ async function autoTakeMedication(
         deletedAt: null,
         takenAt: { not: null },
       },
-      orderBy: { takenAt: "desc" },
+      orderBy: [{ takenAt: "desc" }, { id: "desc" }],
       select: { takenAt: true },
     });
     lastIntakeAt = last?.takenAt ?? null;
diff --git a/src/lib/jobs/reminder/medication-reminder-check.ts b/src/lib/jobs/reminder/medication-reminder-check.ts
index efe367658..eb9596aae 100644
--- a/src/lib/jobs/reminder/medication-reminder-check.ts
+++ b/src/lib/jobs/reminder/medication-reminder-check.ts
@@ -46,6 +46,7 @@ import {
   liveEraStart as liveEraStartOf,
 } from "@/lib/medications/scheduling/live-era";
 import { DEFAULT_TIMEZONE } from "@/lib/tz/format";
+import { MEDICATION_SCHEDULE_ORDER } from "@/lib/medications/read-order";
 
 export interface ReminderCheckPayload {
   triggeredAt: string;
@@ -227,7 +228,7 @@ export async function handleReminderCheck(
       const medications = await prisma.medication.findMany({
         where: { active: true, asNeeded: false, ...TRACKED_INTAKE_WHERE },
         include: {
-          schedules: true,
+          schedules: { orderBy: MEDICATION_SCHEDULE_ORDER },
           phaseConfig: true,
           scheduleRevisions: LIVE_ERA_REVISION_ARGS,
           user: {
@@ -340,13 +341,10 @@ export async function handleReminderCheck(
           a.windowStart.localeCompare(b.windowStart),
         );
 
-        // v1.5.0 — fetch the latest `takenAt` for this medication
-        // once per tick when any schedule on it is rolling. The
-        // canonical recurrence engine needs `lastIntakeAt` to compute
-        // the next-due instant for rolling cadences; calendar
-        // cadences ignore the field, so the fetch is conditional to
-        // avoid an extra round-trip on the common path. Failures bias
-        // toward "treat as never logged" so a flaky DB doesn't
+        // The latest `takenAt` for this medication, once per tick and only
+        // when a schedule on it is rolling: the recurrence engine needs
+        // `lastIntakeAt` for a rolling cadence, a calendar one ignores it.
+        // Failures read as "never logged", so a flaky DB does not
         // suppress reminders.
         const hasRollingSchedule = med.schedules.some(
           (s) => s.rollingIntervalDays !== null,
@@ -362,7 +360,7 @@ export async function handleReminderCheck(
               deletedAt: null,
               takenAt: { not: null },
             },
-            orderBy: { takenAt: "desc" },
+            orderBy: [{ takenAt: "desc" }, { id: "desc" }],
             select: { takenAt: true },
           });
           lastIntakeAt = lastIntake?.takenAt ?? null;
diff --git a/src/lib/mcp/resources.ts b/src/lib/mcp/resources.ts
index 483cbffa7..4092b6e39 100644
--- a/src/lib/mcp/resources.ts
+++ b/src/lib/mcp/resources.ts
@@ -45,6 +45,7 @@ import { getNutrients, NUTRIENT_LABELS } from "@/lib/mcp/nutrients-read";
 import { metricStatusDiscoveryRows } from "@/lib/mcp/rich-reads";
 import { summariseForVisit } from "./doctor-visit-summary";
 import type { McpAuthContext } from "./auth";
+import { MEDICATION_SCHEDULE_ORDER } from "@/lib/medications/read-order";
 
 export interface McpResourceDefinition {
   name: string;
@@ -195,13 +196,13 @@ export const MCP_RESOURCES: McpResourceDefinition[] = [
       const medications = await prisma.medication.findMany({
         where: { userId: ctx.userId },
         include: {
-          schedules: true,
+          schedules: { orderBy: MEDICATION_SCHEDULE_ORDER },
           courses: {
             select: { startsOn: true, endsOn: true },
-            orderBy: { startsOn: "asc" },
+            orderBy: [{ startsOn: "asc" }, { id: "asc" }],
           },
         },
-        orderBy: { createdAt: "desc" },
+        orderBy: [{ createdAt: "desc" }, { id: "desc" }],
       });
       annotate({
         action: { name: "mcp.resource.read" },
@@ -567,7 +568,7 @@ export const MCP_RESOURCE_TEMPLATES: McpResourceTemplateDefinition[] = [
       const meds = await prisma.medication.findMany({
         where: { userId: ctx.userId },
         select: { id: true, name: true, dose: true },
-        orderBy: { createdAt: "desc" },
+        orderBy: [{ createdAt: "desc" }, { id: "desc" }],
         take: 200,
       });
       return meds.map((m) => ({
@@ -585,7 +586,7 @@ export const MCP_RESOURCE_TEMPLATES: McpResourceTemplateDefinition[] = [
       // never another tenant's row.
       const med = await prisma.medication.findFirst({
         where: { id, userId: ctx.userId },
-        include: { schedules: true },
+        include: { schedules: { orderBy: MEDICATION_SCHEDULE_ORDER } },
       });
       annotate({
         action: { name: "mcp.resource.read" },
diff --git a/src/lib/mcp/tools/get-medication-schedule.ts b/src/lib/mcp/tools/get-medication-schedule.ts
index 0b3f06ba9..c69a3a525 100644
--- a/src/lib/mcp/tools/get-medication-schedule.ts
+++ b/src/lib/mcp/tools/get-medication-schedule.ts
@@ -15,6 +15,7 @@ import { dueSchedules } from "@/lib/medications/intake-tracking";
 import { liveEraStartsByMedication } from "@/lib/medications/scheduling/live-era";
 import { MODULE_DISABLED } from "./shared";
 import { READ_ONLY_ANNOTATIONS, type McpToolDefinition } from "./types";
+import { MEDICATION_SCHEDULE_ORDER } from "@/lib/medications/read-order";
 
 // ── Operational reads (not Coach snapshot domains) ──────────────────
 // These answer "what should I do / why is my data stale" rather than "what
@@ -69,8 +70,8 @@ export const getMedicationScheduleTool: McpToolDefinition = {
       }),
       prisma.medication.findMany({
         where: { userId: ctx.userId, active: true },
-        include: { schedules: true },
-        orderBy: { createdAt: "desc" },
+        include: { schedules: { orderBy: MEDICATION_SCHEDULE_ORDER } },
+        orderBy: [{ createdAt: "desc" }, { id: "desc" }],
       }),
     ]);
 
diff --git a/src/lib/medications/compliance-payload.ts b/src/lib/medications/compliance-payload.ts
index 4d30bc45f..992e7825b 100644
--- a/src/lib/medications/compliance-payload.ts
+++ b/src/lib/medications/compliance-payload.ts
@@ -248,7 +248,7 @@ export async function buildCompliancePayload(
       deletedAt: null,
       scheduledFor: { gte: fetchFrom },
     },
-    orderBy: { scheduledFor: "desc" },
+    orderBy: [{ scheduledFor: "desc" }, { id: "desc" }],
     select: {
       takenAt: true,
       skipped: true,
diff --git a/src/lib/medications/courses.ts b/src/lib/medications/courses.ts
index 760b187f9..da6766994 100644
--- a/src/lib/medications/courses.ts
+++ b/src/lib/medications/courses.ts
@@ -125,7 +125,7 @@ async function loadOwned(tx: Tx, userId: string, medicationId: string) {
   if (!medication) throw new CourseWriteError("notFound");
   const courses = await tx.medicationCourse.findMany({
     where: { medicationId },
-    orderBy: { startsOn: "asc" },
+    orderBy: [{ startsOn: "asc" }, { id: "asc" }],
     select: { id: true, startsOn: true, endsOn: true, noteEncrypted: true },
   });
   return { medication, courses };
@@ -423,7 +423,7 @@ export async function checkCurrentWindow(
   const todayKey = userDayKey(args.now ?? new Date(), args.timeZone);
   const courses = await prisma.medicationCourse.findMany({
     where: { medicationId: args.medicationId, userId: args.userId },
-    orderBy: { startsOn: "asc" },
+    orderBy: [{ startsOn: "asc" }, { id: "asc" }],
     select: { id: true, startsOn: true, endsOn: true },
   });
   const latest = courses.at(-1);
@@ -472,7 +472,7 @@ export async function loadCoursesFor(
   if (medicationIds.length === 0) return byMedication;
   const rows = await prisma.medicationCourse.findMany({
     where: { medicationId: { in: medicationIds } },
-    orderBy: { startsOn: "asc" },
+    orderBy: [{ startsOn: "asc" }, { id: "asc" }],
     select: {
       id: true,
       medicationId: true,
diff --git a/src/lib/medications/create-medication.ts b/src/lib/medications/create-medication.ts
index 11162bfe6..609fcc1b3 100644
--- a/src/lib/medications/create-medication.ts
+++ b/src/lib/medications/create-medication.ts
@@ -31,6 +31,7 @@ import {
   medicationDetail,
   type ReadUser,
 } from "@/lib/medications/read-medication";
+import { MEDICATION_SCHEDULE_ORDER } from "@/lib/medications/read-order";
 
 export type CreateMedicationInput = z.output<typeof createMedicationSchema>;
 type ScheduleInput = NonNullable<CreateMedicationInput["schedules"]>[number];
@@ -103,7 +104,7 @@ async function existingMirrorOrCap(
   const userId = user.id;
   const existing = await prisma.medication.findFirst({
     where: { userId, externalSource, externalId },
-    include: { schedules: true },
+    include: { schedules: { orderBy: MEDICATION_SCHEDULE_ORDER } },
   });
   if (existing) {
     return existingMirrorBody(user, existing);
@@ -480,7 +481,7 @@ export async function createMedication(input: {
     if (isP2002 && externalSource !== undefined && externalId !== undefined) {
       const winner = await prisma.medication.findFirst({
         where: { userId: user.id, externalSource, externalId },
-        include: { schedules: true },
+        include: { schedules: { orderBy: MEDICATION_SCHEDULE_ORDER } },
       });
       if (winner) return existingMirrorBody(user, winner);
     }
diff --git a/src/lib/medications/efficacy/build-efficacy.ts b/src/lib/medications/efficacy/build-efficacy.ts
index a1dde1418..9ec5e2065 100644
--- a/src/lib/medications/efficacy/build-efficacy.ts
+++ b/src/lib/medications/efficacy/build-efficacy.ts
@@ -605,7 +605,7 @@ export async function buildMedicationEfficacy(
       deletedAt: null,
       scheduledFor: { gte: fetchFrom },
     },
-    orderBy: { scheduledFor: "desc" },
+    orderBy: [{ scheduledFor: "desc" }, { id: "desc" }],
     select: {
       takenAt: true,
       skipped: true,
diff --git a/src/lib/medications/efficacy/load-segmented-effects.ts b/src/lib/medications/efficacy/load-segmented-effects.ts
index 91923c93a..20cb7783b 100644
--- a/src/lib/medications/efficacy/load-segmented-effects.ts
+++ b/src/lib/medications/efficacy/load-segmented-effects.ts
@@ -176,7 +176,7 @@ export async function loadSegmentedEffects(params: {
         deletedAt: null,
         scheduledFor: { gte: since, lte: until },
       },
-      orderBy: { scheduledFor: "desc" },
+      orderBy: [{ scheduledFor: "desc" }, { id: "desc" }],
       select: {
         takenAt: true,
         skipped: true,
diff --git a/src/lib/medications/intake-slot-dedup.ts b/src/lib/medications/intake-slot-dedup.ts
index 2644489f6..96d1903b8 100644
--- a/src/lib/medications/intake-slot-dedup.ts
+++ b/src/lib/medications/intake-slot-dedup.ts
@@ -226,7 +226,7 @@ export async function dedupeUserIntakeSlots(
       // v1.16.9 — archived eras: an old ad-hoc row converges against the
       // schedule that was live at its takenAt, not today's times.
       scheduleRevisions: {
-        orderBy: { validFrom: "asc" },
+        orderBy: [{ validFrom: "asc" }, { id: "asc" }],
         select: {
           id: true,
           validFrom: true,
@@ -242,15 +242,11 @@ export async function dedupeUserIntakeSlots(
   // recompute after the collapse. Deduped so a busy day folds once.
   const daysToRecompute = new Set<string>();
 
-  // v1.20.2 — batch the per-medication reads. The pre-v1.20.2 shape
-  // issued a `findFirst` (latest takenAt) + a `findMany` (all live rows)
-  // PER medication → 2N round-trips (20 meds = 40). Pull every live row
-  // for the user's medication set in ONE ordered `findMany`, group in
-  // memory by `medicationId`, and derive the per-med `lastIntakeAt` (max
-  // non-null takenAt) from the same grouped set the `findFirst` would
-  // have scanned. The grouping preserves the `scheduledFor asc` order the
-  // snap + heal passes depend on (a stable Postgres sort keeps the
-  // per-medication slices in the same order a per-med query returned).
+  // One ordered read for the user's whole medication set, grouped in memory
+  // by `medicationId`, rather than a `findFirst` and a `findMany` per
+  // medication (2N round-trips). The per-med `lastIntakeAt` comes from the
+  // same rows. The order ends on the id, so each slice holds its rows in the
+  // slot order the snap and heal passes need, the same on every run.
   const medIds = medications
     .filter((m) => m.schedules.length > 0)
     .map((m) => m.id);
@@ -277,7 +273,11 @@ export async function dedupeUserIntakeSlots(
       },
       // `medicationId` first so the per-med slices are contiguous, then the
       // `scheduledFor asc` the loop relies on.
-      orderBy: [{ medicationId: "asc" }, { scheduledFor: "asc" }],
+      orderBy: [
+        { medicationId: "asc" },
+        { scheduledFor: "asc" },
+        { id: "asc" },
+      ],
     })) as DedupIntakeRow[];
 
     for (const row of allRows) {
diff --git a/src/lib/medications/intake-today.ts b/src/lib/medications/intake-today.ts
index 9e6459e2a..fe242840e 100644
--- a/src/lib/medications/intake-today.ts
+++ b/src/lib/medications/intake-today.ts
@@ -43,7 +43,7 @@ export async function readTodayIntakes(input: {
       // medication with intake tracking off is not on it.
       ...TRACKED_INTAKE_EVENT_WHERE,
     },
-    orderBy: { scheduledFor: "asc" },
+    orderBy: [{ scheduledFor: "asc" }, { id: "asc" }],
     include: { medication: { select: { id: true, snoozedUntil: true } } },
   });
 
diff --git a/src/lib/medications/inventory/consumption.ts b/src/lib/medications/inventory/consumption.ts
index dfb0c3c7a..c8116e795 100644
--- a/src/lib/medications/inventory/consumption.ts
+++ b/src/lib/medications/inventory/consumption.ts
@@ -284,6 +284,7 @@ export async function consumeForIntake(input: {
         orderBy: [
           { expiresAt: { sort: "asc", nulls: "last" } },
           { createdAt: "asc" },
+          { id: "asc" },
         ],
       });
       const active = await tx.medicationInventoryItem.findMany({
@@ -297,6 +298,7 @@ export async function consumeForIntake(input: {
           { printedExpiry: { sort: "asc", nulls: "last" } },
           { purchasedAt: { sort: "asc", nulls: "last" } },
           { createdAt: "asc" },
+          { id: "asc" },
         ],
       });
 
@@ -473,6 +475,7 @@ export async function consumeImportedIntakesBatch(input: {
         orderBy: [
           { expiresAt: { sort: "asc", nulls: "last" } },
           { createdAt: "asc" },
+          { id: "asc" },
         ],
       }),
       tx.medicationInventoryItem.findMany({
@@ -486,6 +489,7 @@ export async function consumeImportedIntakesBatch(input: {
           { printedExpiry: { sort: "asc", nulls: "last" } },
           { purchasedAt: { sort: "asc", nulls: "last" } },
           { createdAt: "asc" },
+          { id: "asc" },
         ],
       }),
     ]);
diff --git a/src/lib/medications/list-read.ts b/src/lib/medications/list-read.ts
index a931edb2a..9c916274b 100644
--- a/src/lib/medications/list-read.ts
+++ b/src/lib/medications/list-read.ts
@@ -43,6 +43,7 @@ import { liveEraStartsByMedication } from "@/lib/medications/scheduling/live-era
 import { floorWhole } from "@/lib/medications/units-per-dose";
 import { resolveIntakeActionability } from "@/lib/medications/intake-actionable";
 import { DEFAULT_TIMEZONE } from "@/lib/tz/format";
+import { MEDICATION_SCHEDULE_ORDER } from "@/lib/medications/read-order";
 
 export type MedicationsListResult = Array<Record<string, unknown>>;
 
@@ -55,12 +56,10 @@ export async function buildMedicationsList(
     userTz,
   );
 
-  // v1.15.10 — the slots the user has already acted on near "now", so the
-  // next-due search can skip them. A resolved slot is a taken, deliberately
-  // skipped, or cron-auto-missed row. Bound the window to [today-start,
-  // today-end + 2d] — the next-due lookahead only needs the slots adjacent to
-  // now, and a tight window keeps the read cheap. The 60s list cache covers
-  // the rest.
+  // The slots the user has already acted on near "now" (taken, skipped, or
+  // auto-missed), so the next-due search can skip them. The lookahead only
+  // needs the slots next to now, so the window ends two days past today; the
+  // 60s list cache covers the rest.
   const resolvedWindowEnd = new Date(
     todayEndUtc.getTime() + 2 * 24 * 60 * 60 * 1000,
   );
@@ -84,8 +83,11 @@ export async function buildMedicationsList(
     prisma.medication.findMany({
       where: { userId },
       // v1.43 — the ingredient count only, for `hasIngredients`.
-      include: { schedules: true, _count: { select: { ingredients: true } } },
-      orderBy: { createdAt: "desc" },
+      include: {
+        schedules: { orderBy: MEDICATION_SCHEDULE_ORDER },
+        _count: { select: { ingredients: true } },
+      },
+      orderBy: [{ createdAt: "desc" }, { id: "desc" }],
     }),
     prisma.medicationIntakeEvent.groupBy({
       by: ["medicationId"],
@@ -100,13 +102,11 @@ export async function buildMedicationsList(
     }),
     prisma.medicationIntakeEvent.groupBy({
       by: ["medicationId"],
-      // v1.7.0 sync — exclude tombstoned rows from the today-count map.
-      // v1.16.9 — count only ACTIONED rows (taken or skipped). The
-      // dashboard projector mints pending rows for every slot of the
-      // day, so counting all rows made `todayEventCount` cover every
-      // passed dose after any dashboard visit — and the cards'
-      // overdue-pill suppression (`todayEventCount < passedDoseCount`)
-      // went dark nondeterministically for genuinely overdue doses.
+      // Live, ACTIONED rows only (taken or skipped). The dashboard projector
+      // mints pending rows for every slot of the day, so counting all rows
+      // made `todayEventCount` cover every passed dose after any dashboard
+      // visit, and the cards' overdue pill (`todayEventCount <
+      // passedDoseCount`) went dark for genuinely overdue doses.
       where: {
         userId,
         deletedAt: null,
diff --git a/src/lib/medications/read-medication.ts b/src/lib/medications/read-medication.ts
index 248235e3e..6f7adea8d 100644
--- a/src/lib/medications/read-medication.ts
+++ b/src/lib/medications/read-medication.ts
@@ -63,7 +63,7 @@ async function loadDisplayDue(
           deletedAt: null,
           takenAt: { not: null },
         },
-        orderBy: { takenAt: "desc" },
+        orderBy: [{ takenAt: "desc" }, { id: "desc" }],
         select: { takenAt: true },
       })
     : null;
@@ -94,7 +94,7 @@ async function loadDisplayDue(
     // Superseded rows are audit records — a correction may have
     // shortened the era, so the boundary reads only active rows.
     where: { medicationId: id, supersededByRevisionId: null },
-    orderBy: { validUntil: "desc" },
+    orderBy: [{ validUntil: "desc" }, { id: "desc" }],
     select: { validUntil: true },
   });
   // Intake tracking off (#1033): nothing is due from the stored rows, and no
diff --git a/src/lib/medications/read-order.ts b/src/lib/medications/read-order.ts
new file mode 100644
index 000000000..766cdf9db
--- /dev/null
+++ b/src/lib/medications/read-order.ts
@@ -0,0 +1,22 @@
+/**
+ * The order a medication's rows are read in, ties included.
+ *
+ * Postgres returns rows that tie on an `ORDER BY` in no particular order, and
+ * not the same order twice: the heap layout, a vacuum or a parallel plan all
+ * change it. A read ordered by a column two rows can share (two schedules at
+ * 08:00 on different medications, two intakes in the same slot, two
+ * medications created in one import) therefore answered its client a
+ * different order from one request to the next, and a "latest" lookup picked
+ * either of two rows. Every medication and intake read ends its order on the
+ * row id, and `medication-read-order-guard.test.ts` holds the tree to it.
+ */
+import type { Prisma } from "@/generated/prisma/client";
+
+/**
+ * A medication's schedules, as every reader that hands them on includes
+ * them: by window, then by id, the order the backup already writes.
+ */
+export const MEDICATION_SCHEDULE_ORDER = [
+  { windowStart: "asc" },
+  { id: "asc" },
+] as const satisfies Prisma.MedicationScheduleOrderByWithRelationInput[];
diff --git a/src/lib/medications/record-intake/write.ts b/src/lib/medications/record-intake/write.ts
index 4db4ca049..20371010e 100644
--- a/src/lib/medications/record-intake/write.ts
+++ b/src/lib/medications/record-intake/write.ts
@@ -66,7 +66,7 @@ export async function findReplayedIntake(
         skipped,
         createdAt: { gte: new Date(Date.now() - 60_000) },
       },
-      orderBy: { createdAt: "desc" },
+      orderBy: [{ createdAt: "desc" }, { id: "desc" }],
     });
     if (recentDuplicate) {
       return recentDuplicate;
diff --git a/src/lib/medications/scheduling/project-today-intakes.ts b/src/lib/medications/scheduling/project-today-intakes.ts
index f7c1863f7..20bfd2354 100644
--- a/src/lib/medications/scheduling/project-today-intakes.ts
+++ b/src/lib/medications/scheduling/project-today-intakes.ts
@@ -123,7 +123,7 @@ export async function projectTodayIntakesAndRecompute(input: {
           deletedAt: null,
           takenAt: { not: null },
         },
-        orderBy: { takenAt: "desc" },
+        orderBy: [{ takenAt: "desc" }, { id: "desc" }],
         select: { takenAt: true },
       });
       lastIntakeAt = lastIntake?.takenAt ?? null;
diff --git a/src/lib/medications/scheduling/slot-upsert.ts b/src/lib/medications/scheduling/slot-upsert.ts
index 13a791050..01fed425f 100644
--- a/src/lib/medications/scheduling/slot-upsert.ts
+++ b/src/lib/medications/scheduling/slot-upsert.ts
@@ -548,7 +548,7 @@ export async function resolveSlotInstantForWrite(
         deletedAt: null,
         takenAt: { not: null },
       },
-      orderBy: { takenAt: "desc" },
+      orderBy: [{ takenAt: "desc" }, { id: "desc" }],
       select: { takenAt: true },
     });
     lastIntakeAt = lastIntake?.takenAt ?? null;
@@ -603,7 +603,7 @@ async function loadAttributeMedication(input: {
         deletedAt: null,
         takenAt: { not: null },
       },
-      orderBy: { takenAt: "desc" },
+      orderBy: [{ takenAt: "desc" }, { id: "desc" }],
       select: { takenAt: true },
     });
     lastIntakeAt = lastIntake?.takenAt ?? null;
@@ -905,7 +905,7 @@ async function rollingIntakeInstantsIfNeeded(
       skipped: false,
       takenAt: { not: null, lte: around },
     },
-    orderBy: { takenAt: "asc" },
+    orderBy: [{ takenAt: "asc" }, { id: "asc" }],
     select: { takenAt: true },
   });
   return rows.map((r) => r.takenAt).filter((d): d is Date => d !== null);
diff --git a/src/lib/medications/update-medication/preflight.ts b/src/lib/medications/update-medication/preflight.ts
index 5becef569..05eb8ce57 100644
--- a/src/lib/medications/update-medication/preflight.ts
+++ b/src/lib/medications/update-medication/preflight.ts
@@ -189,7 +189,7 @@ export async function findPrimaryScheduleGracePatch(
   if (topLevelGraceMinutes !== undefined && !schedules) {
     const primary = await prisma.medicationSchedule.findFirst({
       where: { medicationId: id },
-      orderBy: { windowStart: "asc" },
+      orderBy: [{ windowStart: "asc" }, { id: "asc" }],
       select: { id: true },
     });
     if (primary) {
diff --git a/src/lib/medications/update-medication/write.ts b/src/lib/medications/update-medication/write.ts
index c15b69575..f210ddb0d 100644
--- a/src/lib/medications/update-medication/write.ts
+++ b/src/lib/medications/update-medication/write.ts
@@ -164,7 +164,7 @@ async function archiveEra(
     // Chain from the ACTIVE boundary: a superseded row is an
     // audit record whose `validUntil` may sit past its correction.
     where: { medicationId: id, supersededByRevisionId: null },
-    orderBy: { validUntil: "desc" },
+    orderBy: [{ validUntil: "desc" }, { id: "desc" }],
     select: { validUntil: true },
   });
   await tx.medicationScheduleRevision.create({
diff --git a/src/lib/targets/build-response.ts b/src/lib/targets/build-response.ts
index ac8ad62ce..1c28f8775 100644
--- a/src/lib/targets/build-response.ts
+++ b/src/lib/targets/build-response.ts
@@ -175,12 +175,12 @@ export async function buildTargetsResponse(user: AuthedUser) {
         },
         include: {
           schedules: { select: SCHEDULE_COMPLIANCE_SELECT },
-          scheduleRevisions: { orderBy: { validFrom: "asc" } },
+          scheduleRevisions: { orderBy: [{ validFrom: "asc" }, { id: "asc" }] },
           pauseEras: { select: { pausedAt: true, resumedAt: true } },
           // v1.40 (#1024) — the courses, so a gap between two expects nothing.
           courses: COURSES_COMPLIANCE_SELECT,
         },
-        orderBy: { name: "asc" },
+        orderBy: [{ name: "asc" }, { id: "asc" }],
       });
       if (activeMedications.length === 0) {
         return { activeMedications, intakeEvents: [] };
@@ -194,7 +194,7 @@ export async function buildTargetsResponse(user: AuthedUser) {
           },
           scheduledFor: { gte: thirtyDaysAgo },
         },
-        orderBy: { scheduledFor: "desc" },
+        orderBy: [{ scheduledFor: "desc" }, { id: "desc" }],
         select: {
           medicationId: true,
           takenAt: true,
diff --git a/src/lib/telegram-webhook-handlers.ts b/src/lib/telegram-webhook-handlers.ts
index 7b7bdf7c2..23301c3eb 100644
--- a/src/lib/telegram-webhook-handlers.ts
+++ b/src/lib/telegram-webhook-handlers.ts
@@ -1164,7 +1164,7 @@ export async function handleTextMessage(update: TelegramUpdate) {
     const meds = await prisma.medication.findMany({
       where: { userId: user.id, active: true, ...TRACKED_INTAKE_WHERE },
       select: { id: true, name: true, dose: true },
-      orderBy: { name: "asc" },
+      orderBy: [{ name: "asc" }, { id: "asc" }],
     });
 
     if (meds.length === 0) {
@@ -1280,7 +1280,7 @@ export async function handleTextMessage(update: TelegramUpdate) {
     const meds = await prisma.medication.findMany({
       where: { userId: user.id, active: true, ...TRACKED_INTAKE_WHERE },
       select: { id: true, name: true },
-      orderBy: { name: "asc" },
+      orderBy: [{ name: "asc" }, { id: "asc" }],
       take: 2,
     });
     if (meds.length === 1) {
diff --git a/src/lib/timeline/lanes.ts b/src/lib/timeline/lanes.ts
index 73fdb5789..eeb0f9053 100644
--- a/src/lib/timeline/lanes.ts
+++ b/src/lib/timeline/lanes.ts
@@ -238,7 +238,7 @@ async function medicationsLane(frame: LaneFrame): Promise<LaneRead> {
         endsOn: true,
         updatedAt: true,
       },
-      orderBy: { createdAt: "asc" },
+      orderBy: [{ createdAt: "asc" }, { id: "asc" }],
     }),
     prisma.medicationIntakeEvent.groupBy({
       by: ["medicationId"],
diff --git a/src/lib/timeline/readiness.ts b/src/lib/timeline/readiness.ts
index dcafc0d9a..a65e313d4 100644
--- a/src/lib/timeline/readiness.ts
+++ b/src/lib/timeline/readiness.ts
@@ -285,7 +285,7 @@ async function medicationsLane(frame: Frame) {
     prisma.medication.findMany({
       where: { userId: frame.userId },
       select: { id: true, startsOn: true },
-      orderBy: { createdAt: "asc" },
+      orderBy: [{ createdAt: "asc" }, { id: "asc" }],
     }),
     prisma.medicationIntakeEvent.groupBy({
       by: ["medicationId"],
diff --git a/tests/integration/medication-read-order.test.ts b/tests/integration/medication-read-order.test.ts
new file mode 100644
index 000000000..861798255
--- /dev/null
+++ b/tests/integration/medication-read-order.test.ts
@@ -0,0 +1,120 @@
+/**
+ * Medication rows that tie on their sort key come back in one order.
+ *
+ * Postgres answers rows that tie on an `ORDER BY` in no particular order;
+ * with nothing to break the tie a small table hands them back as they lie in
+ * the heap, which is the order they were written in. Each case below writes
+ * its tying rows in the opposite order to the one the read promises, so a read
+ * that lost its tie-breaker answers the heap order and fails, and does so on
+ * the first run rather than on an unlucky one:
+ *
+ *   - two medications created in the same millisecond (an import writes many)
+ *     are listed newest first, then by id;
+ *   - two schedules of one medication in the same window come back by id;
+ *   - two of today's intakes on the same instant (two medications due at
+ *     08:00) come back by id.
+ */
+import { afterAll, beforeAll, describe, expect, it } from "vitest";
+
+import { GET as listMedications } from "@/app/api/medications/route";
+import { GET as listIntakes } from "@/app/api/medications/intake/route";
+
+import { callRoute } from "../kit/call-route";
+import { makeSession, makeUser } from "../kit/factories";
+import { getPrismaClient, truncateAllTables } from "./setup";
+
+const prisma = getPrismaClient();
+
+const CREATED = new Date("2026-10-01T09:00:00.000Z");
+
+beforeAll(async () => {
+  await truncateAllTables(prisma);
+});
+
+afterAll(async () => {
+  await truncateAllTables(prisma);
+});
+
+describe("medication reads with tying sort keys", () => {
+  it("lists two medications created together newest first, then by id", async () => {
+    const user = await makeUser({ timezone: "Europe/Berlin" });
+    // Written a, then b; the list promises createdAt desc, id desc: b, a.
+    for (const id of ["ord-med-a", "ord-med-b"]) {
+      await prisma.medication.create({
+        data: {
+          id,
+          userId: user.id,
+          name: id,
+          dose: "5 mg",
+          createdAt: CREATED,
+        },
+      });
+    }
+    // Written b, then a, in one window; the list promises window, id: a, b.
+    for (const id of ["ord-sched-b", "ord-sched-a"]) {
+      await prisma.medicationSchedule.create({
+        data: {
+          id,
+          medicationId: "ord-med-a",
+          windowStart: "08:00",
+          windowEnd: "09:00",
+        },
+      });
+    }
+
+    const res = await callRoute<
+      Array<{ id: string; schedules: Array<{ id: string }> }>
+    >(listMedications, {
+      method: "GET",
+      route: "/api/medications",
+      auth: await makeSession(user),
+    });
+    expect(res.status).toBe(200);
+    expect(res.data.map((m) => m.id)).toEqual(["ord-med-b", "ord-med-a"]);
+    const a = res.data.find((m) => m.id === "ord-med-a")!;
+    expect(a.schedules.map((s) => s.id)).toEqual([
+      "ord-sched-a",
+      "ord-sched-b",
+    ]);
+  });
+
+  it("lists today's intakes on one instant by id", async () => {
+    const user = await makeUser({ timezone: "UTC" });
+    const now = new Date();
+    const due = new Date(
+      Date.UTC(now.getUTCFullYear(), now.getUTCMonth(), now.getUTCDate(), 0, 1),
+    );
+    for (const [medicationId, intakeId] of [
+      ["ord-today-med-1", "ord-intake-b"],
+      ["ord-today-med-2", "ord-intake-a"],
+    ] as const) {
+      await prisma.medication.create({
+        data: {
+          id: medicationId,
+          userId: user.id,
+          name: medicationId,
+          dose: "1",
+        },
+      });
+      // Written b, then a; the read promises scheduledFor asc, id asc: a, b.
+      await prisma.medicationIntakeEvent.create({
+        data: {
+          id: intakeId,
+          userId: user.id,
+          medicationId,
+          scheduledFor: due,
+          takenAt: due,
+        },
+      });
+    }
+
+    const res = await callRoute<Array<{ id: string }>>(listIntakes, {
+      method: "GET",
+      route: "/api/medications/intake",
+      query: { scope: "today" },
+      auth: await makeSession(user),
+    });
+    expect(res.status).toBe(200);
+    expect(res.data.map((e) => e.id)).toEqual(["ord-intake-a", "ord-intake-b"]);
+  });
+});
diff --git a/tests/integration/routes/parity/medication-state.ts b/tests/integration/routes/parity/medication-state.ts
index b96f6b348..4790ff2c8 100644
--- a/tests/integration/routes/parity/medication-state.ts
+++ b/tests/integration/routes/parity/medication-state.ts
@@ -96,7 +96,16 @@ function orderKey(value: unknown): string {
   });
 }
 
-/** Rows in content order, ids and stamps left out of the comparison. */
+/**
+ * Rows in content order, ids and stamps left out of the comparison.
+ *
+ * Two rows can share their whole content once the ids are out (a schedule at
+ * 08:00 on each of two medications), and the sort keeps them in the order the
+ * read returned them. So every read below is ordered by id, which for a cuid
+ * is the order the rows were written in: an unordered read handed the ties
+ * back in whatever order the heap held them, and their `<id:N>` labels
+ * swapped under a loaded run.
+ */
 export function sortRows<T>(rows: readonly T[]): unknown[] {
   return rows
     .map(plain)
@@ -112,6 +121,8 @@ export function sortRows<T>(rows: readonly T[]): unknown[] {
  * guard writes them fire-and-forget, so whether one has landed when the test
  * reads is a race, not something the route decides.
  */
+const BY_ID = { id: "asc" } as const;
+
 export async function medicationState(prisma: Client, userIds: string[]) {
   const byUser = { userId: { in: userIds } };
   const byMedication = { medication: byUser };
@@ -130,19 +141,35 @@ export async function medicationState(prisma: Client, userIds: string[]) {
     audit,
     idempotency,
   ] = await Promise.all([
-    prisma.medication.findMany({ where: byUser }),
-    prisma.medicationSchedule.findMany({ where: byMedication }),
-    prisma.medicationScheduleRevision.findMany({ where: byMedication }),
-    prisma.medicationPauseEra.findMany({ where: byMedication }),
-    prisma.medicationCourse.findMany({ where: byMedication }),
-    prisma.medicationIntakeEvent.findMany({ where: byUser }),
-    prisma.medicationDoseChange.findMany({ where: byMedication }),
-    prisma.medicationInventoryItem.findMany({ where: byUser }),
-    prisma.medicationInventoryEvent.findMany({ where: byMedication }),
-    prisma.medicationCategoryAssignment.findMany({ where: byMedication }),
-    prisma.medicationIngredient.findMany({ where: byMedication }),
+    prisma.medication.findMany({ where: byUser, orderBy: BY_ID }),
+    prisma.medicationSchedule.findMany({ where: byMedication, orderBy: BY_ID }),
+    prisma.medicationScheduleRevision.findMany({
+      where: byMedication,
+      orderBy: BY_ID,
+    }),
+    prisma.medicationPauseEra.findMany({ where: byMedication, orderBy: BY_ID }),
+    prisma.medicationCourse.findMany({ where: byMedication, orderBy: BY_ID }),
+    prisma.medicationIntakeEvent.findMany({ where: byUser, orderBy: BY_ID }),
+    prisma.medicationDoseChange.findMany({
+      where: byMedication,
+      orderBy: BY_ID,
+    }),
+    prisma.medicationInventoryItem.findMany({ where: byUser, orderBy: BY_ID }),
+    prisma.medicationInventoryEvent.findMany({
+      where: byMedication,
+      orderBy: BY_ID,
+    }),
+    prisma.medicationCategoryAssignment.findMany({
+      where: byMedication,
+      orderBy: { medicationId: "asc" },
+    }),
+    prisma.medicationIngredient.findMany({
+      where: byMedication,
+      orderBy: BY_ID,
+    }),
     prisma.auditLog.findMany({
       where: { ...byUser, action: { notIn: [...GUARD_TRAIL_ACTIONS] } },
+      orderBy: BY_ID,
       select: {
         action: true,
         userId: true,
@@ -153,6 +180,7 @@ export async function medicationState(prisma: Client, userIds: string[]) {
     }),
     prisma.idempotencyKey.findMany({
       where: byUser,
+      orderBy: BY_ID,
       select: {
         userId: true,
         key: true,