diff --git a/src/app/api/insights/generate/route.ts b/src/app/api/insights/generate/route.ts
index c17109db5..271389d2b 100644
--- a/src/app/api/insights/generate/route.ts
+++ b/src/app/api/insights/generate/route.ts
@@ -68,6 +68,7 @@ import { apiHandler, requireAuth } from "@/lib/api-handler";
 import { requireAssistantSurface } from "@/lib/feature-flags";
 import { invalidateUserInsights } from "@/lib/cache/invalidate";
 import { annotate } from "@/lib/logging/context";
+import { toProfileSex } from "@/lib/profile/sex";
 import { resolveServerLocale } from "@/lib/i18n/server-locale";
 import { normalizeLocale } from "@/lib/insights/status-shared";
 import { hasUsableStatusProvider } from "@/lib/insights/status-provider";
@@ -597,10 +598,7 @@ export const POST = apiHandler((request: NextRequest) =>
     // v1.10.0 — fold a notable derived wellness signal (readiness / recovery
     // shift, confidence-gated) into the briefing as a SYSTEM CONTEXT block.
     // Reads the one derived contract; null (the common case) costs nothing.
-    const derivedSex =
-      dbUser?.gender === "MALE" || dbUser?.gender === "FEMALE"
-        ? (dbUser.gender as "MALE" | "FEMALE")
-        : null;
+    const derivedSex = toProfileSex(dbUser?.gender);
     const derivedBriefing = await detectDerivedBriefingSignals(userId, {
       ageYears: getAgeFromDateOfBirth(dbUser?.dateOfBirth ?? null),
       sex: derivedSex,
diff --git a/src/components/onboarding/baseline-form.tsx b/src/components/onboarding/baseline-form.tsx
index b1ba7f94d..f905c1ca1 100644
--- a/src/components/onboarding/baseline-form.tsx
+++ b/src/components/onboarding/baseline-form.tsx
@@ -29,6 +29,7 @@ import { useTranslations } from "@/lib/i18n/context";
 import { apiGet, apiPost, apiPut } from "@/lib/api/api-fetch";
 import { localizedApiError } from "@/lib/api/localized-error";
 import { queryKeys } from "@/lib/query-keys";
+import { toProfileSex } from "@/lib/profile/sex";
 import {
   AnamnesisCard,
   buildAnamnesisAboutMeBody,
@@ -139,13 +140,11 @@ export function BaselineForm() {
         const heightCm = heightAdapter.toCanonicalCm(form.height);
         if (heightCm !== null) profileBody.heightCm = heightCm;
         if (form.dateOfBirth) profileBody.dateOfBirth = form.dateOfBirth;
-        if (
-          form.gender === "MALE" ||
-          form.gender === "FEMALE" ||
-          form.gender === "OTHER"
-        ) {
-          profileBody.gender = form.gender;
-        }
+        // Every value the profile stores travels; the guard drops only the
+        // "prefer not to say" placeholder. It used to list two of the three
+        // by hand, so a third-value answer vanished on submit without a word.
+        const gender = toProfileSex(form.gender);
+        if (gender) profileBody.gender = gender;
         if (Object.keys(profileBody).length > 0) {
           await apiPut("/api/auth/profile", profileBody);
         }
diff --git a/src/lib/ai/coach/snapshot.ts b/src/lib/ai/coach/snapshot.ts
index ae160c7f2..f6cbe5fcc 100644
--- a/src/lib/ai/coach/snapshot.ts
+++ b/src/lib/ai/coach/snapshot.ts
@@ -53,6 +53,7 @@ import { resolveModuleMap, type ModuleKey } from "@/lib/modules/gate";
 import { MODULE_SCOPED_SOURCES } from "@/lib/modules/measurement-scope";
 import { SCHEDULE_COMPLIANCE_SELECT } from "@/lib/analytics/compliance";
 import type { BaselineProfile } from "@/lib/insights/derived";
+import { toProfileSex } from "@/lib/profile/sex";
 import {
   CLUSTER_PRIORITY,
   clusterSourcesFromPrefs,
@@ -691,10 +692,7 @@ async function buildCoachSnapshotImpl(
   const derivedCtx = features.context;
   const derivedProfile: BaselineProfile = {
     ageYears: derivedCtx?.ageYears ?? null,
-    sex:
-      derivedCtx?.gender === "MALE" || derivedCtx?.gender === "FEMALE"
-        ? (derivedCtx.gender as "MALE" | "FEMALE")
-        : null,
+    sex: toProfileSex(derivedCtx?.gender),
     heightCm: derivedCtx?.heightCm ?? null,
   };
   // v1.18.0 — the derived block + WHOOP-native dayStrain + trajectory are
diff --git a/src/lib/dashboard/__tests__/snapshot.test.ts b/src/lib/dashboard/__tests__/snapshot.test.ts
index 19ef63e60..288e2c39f 100644
--- a/src/lib/dashboard/__tests__/snapshot.test.ts
+++ b/src/lib/dashboard/__tests__/snapshot.test.ts
@@ -1276,3 +1276,32 @@ describe("buildDashboardSnapshot — scoreRings wire", () => {
     expect(snap.tiles.summaries.WEIGHT).toBeDefined();
   });
 });
+
+describe("buildDashboardSnapshot — the wire carries the stored gender", () => {
+  beforeEach(() => {
+    // Prime only what the user block needs; this suite must not inherit
+    // another test's mock state.
+    probeRollupCoverage.mockResolvedValue(new Map());
+    isFullyCovered.mockReturnValue(false);
+    computeBpInTargetFastPath.mockResolvedValue(null);
+  });
+
+  it("emits OTHER rather than flattening it to no answer", async () => {
+    // Narrowing to two values on the wire made an account that answered
+    // OTHER indistinguishable from one that answered nothing, on every
+    // client reading this payload.
+    const snap = await buildDashboardSnapshot(
+      fakePrisma,
+      baseUser({ gender: "OTHER" }),
+    );
+    expect(snap.user.gender).toBe("OTHER");
+  });
+
+  it("still reports no answer as null", async () => {
+    const snap = await buildDashboardSnapshot(
+      fakePrisma,
+      baseUser({ gender: null }),
+    );
+    expect(snap.user.gender).toBeNull();
+  });
+});
diff --git a/src/lib/doctor-report-pdf/__tests__/header-profile-gender.test.ts b/src/lib/doctor-report-pdf/__tests__/header-profile-gender.test.ts
new file mode 100644
index 000000000..ce126d2b5
--- /dev/null
+++ b/src/lib/doctor-report-pdf/__tests__/header-profile-gender.test.ts
@@ -0,0 +1,93 @@
+import { describe, it, expect, vi } from "vitest";
+import { buildHeaderProfileSection } from "../header-profile-section";
+import type {
+  DoctorReportPdfRenderContext,
+  DoctorReportPdfCursorState,
+} from "../render-context";
+
+/**
+ * A line on a clinical cover sheet is a positive claim about the patient.
+ * The gender row used to label ANY unrecognised stored string as the third
+ * value, so a legacy or malformed value asserted something the account
+ * never chose. Absence has to read as absence.
+ */
+function renderPatientLines(gender: string | null): string[] {
+  const lines: string[] = [];
+  const doc = {
+    setFontSize: vi.fn(),
+    setFont: vi.fn(),
+    setTextColor: vi.fn(),
+    setDrawColor: vi.fn(),
+    setLineWidth: vi.fn(),
+    line: vi.fn(),
+    addPage: vi.fn(),
+    getNumberOfPages: () => 1,
+    splitTextToSize: (s: string) => [s],
+    text: (line: string) => {
+      lines.push(line);
+    },
+    internal: { pageSize: { getWidth: () => 210, getHeight: () => 297 } },
+  };
+  const context = {
+    doc,
+    data: {
+      patient: {
+        username: "testuser",
+        fullName: null,
+        dateOfBirth: null,
+        gender,
+        heightCm: null,
+        insurerName: null,
+        insurerIkNumber: null,
+      },
+      period: {
+        since: "2026-06-01T00:00:00.000Z",
+        start: null,
+        end: null,
+        days: 30,
+      },
+      practiceName: null,
+      measurements: {},
+      stats: {},
+      compliance: {},
+    },
+    // The translator echoes the key so an assertion can name the label it
+    // expects instead of a locale string.
+    t: (key: string) => key,
+    num: (value: number) => String(value),
+    fmtDate: (iso: string) => iso.slice(0, 10),
+    now: new Date("2026-07-26T00:00:00.000Z"),
+    insuranceNumber: null,
+    margin: 15,
+    pageWidth: 210,
+    contentMaxY: 280,
+    ensureSpace: (current: number) => current,
+  } as unknown as DoctorReportPdfRenderContext;
+  buildHeaderProfileSection(context, {
+    y: 20,
+  } as unknown as DoctorReportPdfCursorState);
+  return lines;
+}
+
+describe("doctor-report cover — gender row", () => {
+  it("labels each of the three stored values", () => {
+    expect(renderPatientLines("MALE")).toContain(
+      "doctorReport.gender: doctorReport.genderMale",
+    );
+    expect(renderPatientLines("FEMALE")).toContain(
+      "doctorReport.gender: doctorReport.genderFemale",
+    );
+    expect(renderPatientLines("OTHER")).toContain(
+      "doctorReport.gender: doctorReport.genderOther",
+    );
+  });
+
+  it("omits the row entirely for no answer or an unrecognised value", () => {
+    for (const stored of [null, "", "diverse", "male"]) {
+      const lines = renderPatientLines(stored);
+      expect(
+        lines.some((line) => line.startsWith("doctorReport.gender:")),
+      ).toBe(false);
+    }
+  });
+});
diff --git a/src/lib/profile/__tests__/sex.test.ts b/src/lib/profile/__tests__/sex.test.ts
new file mode 100644
index 000000000..bd0d8dad9
--- /dev/null
+++ b/src/lib/profile/__tests__/sex.test.ts
@@ -0,0 +1,38 @@
+import { describe, it, expect } from "vitest";
+import { toProfileSex, binaryReferenceSex } from "@/lib/profile/sex";
+
+/**
+ * The column holds three values. Two separate defects shipped from code
+ * that could only hold two: the FHIR export mapped the third to `female`,
+ * and the Strain model scored it on the male coefficients. These two
+ * functions are the only sanctioned way to move between the widths.
+ */
+describe("toProfileSex", () => {
+  it("carries every stored value through", () => {
+    expect(toProfileSex("MALE")).toBe("MALE");
+    expect(toProfileSex("FEMALE")).toBe("FEMALE");
+    expect(toProfileSex("OTHER")).toBe("OTHER");
+  });
+
+  it("reports no answer as no answer, and never guesses one", () => {
+    expect(toProfileSex(null)).toBeNull();
+    expect(toProfileSex(undefined)).toBeNull();
+    expect(toProfileSex("")).toBeNull();
+    expect(toProfileSex("male")).toBeNull();
+    expect(toProfileSex("diverse")).toBeNull();
+  });
+});
+
+describe("binaryReferenceSex", () => {
+  it("keeps the two values a sex-split reference table has rows for", () => {
+    expect(binaryReferenceSex("MALE")).toBe("MALE");
+    expect(binaryReferenceSex("FEMALE")).toBe("FEMALE");
+  });
+
+  it("resolves the third value to null rather than to one of the two", () => {
+    expect(binaryReferenceSex("OTHER")).toBeNull();
+    expect(binaryReferenceSex(null)).toBeNull();
+    expect(binaryReferenceSex(undefined)).toBeNull();
+    expect(binaryReferenceSex("")).toBeNull();
+  });
+});