feat(medications): as-needed medications log without a schedule

A medication can declare itself as-needed: no schedules, never due,
never reminded, excluded from every compliance rate — but intakes log
ad-hoc, consume inventory exactly like scheduled doses, and the
history stays. The wizard offers it as a cadence choice and round-
trips it on edit; card, table and detail show a calm marker where the
next dose normally sits, the take-all dialog never collects one, and
the supply runway stays unknowable by construction. (#316)

src/components/medications/__tests__/medication-card-next-due.test.tsx

@@ -295,3 +295,75 @@ describe("<MedicationCard> — open overdue slot (v1.16.4)", () => {
     expect(html).not.toContain("can still be taken");
   });
 });
+
+/**
+ * v1.16.11 (#316) — as-needed (PRN) card presentation: a calm
+ * "As needed" marker where next-due normally sits, no due pill, no
+ * overdue escalation, and NO compliance block (neither bars nor an
+ * eternal skeleton — the batched compliance read excludes PRN rows).
+ * The last-intake line stays: the card is last-taken oriented.
+ */
+describe("<MedicationCard> — as-needed marker (v1.16.11, #316)", () => {
+  function makeAsNeededMed(overrides: Record<string, unknown> = {}) {
+    const lastTaken = new Date();
+    lastTaken.setHours(lastTaken.getHours() - 3);
+    return {
+      id: "med-prn-1",
+      name: "Ibuprofen",
+      dose: "400 mg",
+      category: "PAIN_RELIEF",
+      treatmentClass: undefined as string | undefined,
+      active: true,
+      notificationsEnabled: true,
+      pausedAt: null,
+      lastTakenAt: lastTaken.toISOString(),
+      todayEventCount: 1,
+      nextDueAt: null,
+      nextDueOverdue: false,
+      asNeeded: true,
+      schedules: [],
+      ...overrides,
+    };
+  }
+
+  it("renders the calm marker, the last-intake line, and no compliance block", () => {
+    const med = makeAsNeededMed();
+    const client = makeClient();
+    // Deliberately NOT seeding the compliance cache: the batched read
+    // excludes as-needed medications, so the card must not fall back to
+    // the loading skeleton.
+    const html = render(
+      <MedicationCard
+        medication={med}
+        onEdit={() => {}}
+        onOpenHistory={() => {}}
+      />,
+      client,
+    );
+
+    expect(html).toContain('data-slot="medication-as-needed-marker"');
+    expect(html).toContain("As needed");
+    expect(html).toContain("Last intake:");
+    // No due/overdue presentation, ever.
+    expect(html).not.toContain("Overdue");
+    expect(html).not.toContain("Take now");
+    // No compliance bars and no skeleton placeholder for them.
+    expect(html).not.toContain("Adherence (");
+  });
+
+  it("keeps the quick-log action row (intakes still record)", () => {
+    const med = makeAsNeededMed();
+    const client = makeClient();
+    const html = render(
+      <MedicationCard
+        medication={med}
+        onEdit={() => {}}
+        onOpenHistory={() => {}}
+      />,
+      client,
+    );
+    // The shared intake actions render (take/skip) — an as-needed dose
+    // is loggable from the card exactly like a scheduled one.
+    expect(html).toContain("Taken");
+  });
+});

src/components/medications/__tests__/medication-table.test.tsx

@@ -261,6 +261,43 @@ describe("<MedicationTable> — structure + shared payloads", () => {
     expect(html).toContain('aria-label="Take – Mounjaro"');
     expect(html).toContain("4 doses");
   });
+
+  it("renders an as-needed row: calm marker, no compliance bars (v1.16.11 #316)", () => {
+    const client = makeClient();
+    // Deliberately NOT seeding compliance for the PRN row — the batched
+    // payload excludes as-needed medications, and the column must show
+    // the en-dash instead of an eternal skeleton.
+    const lastTaken = new Date();
+    lastTaken.setHours(lastTaken.getHours() - 3);
+    const html = render(
+      <MedicationTable
+        activeMedications={[
+          med({
+            id: "prn1",
+            name: "Ibuprofen",
+            asNeeded: true,
+            schedules: [],
+            nextDueAt: null,
+            lastTakenAt: lastTaken.toISOString(),
+            stockDosesRemaining: 10,
+          }),
+        ]}
+        inactiveMedications={[]}
+      />,
+      client,
+    );
+
+    expect(html).toContain('data-slot="medication-table-as-needed-marker"');
+    expect(html).toContain("As needed");
+    // No due/overdue presentation in the status or next-dose cells.
+    expect(html).not.toContain("Overdue");
+    // Compliance column shows the en-dash, not bars or a skeleton.
+    expect(html).not.toContain("Adherence (");
+    // The quick actions stay — an as-needed dose is loggable inline.
+    expect(html).toContain('aria-label="Take – Ibuprofen"');
+    // Stock column still renders (inventory tracking works for PRN).
+    expect(html).toContain("10 doses");
+  });
 });
 
 describe("<MedicationTable> — manual order + aria-sort", () => {

src/components/medications/__tests__/take-all-due.test.tsx

@@ -195,6 +195,26 @@ describe("deriveDueMedications — only currently-due, active, unpaused", () =>
     expect(due).toEqual([]);
   });
 
+  it("excludes an as-needed medication (no schedules, never due) — v1.16.11 #316", () => {
+    // An as-needed (PRN) medication persists ZERO schedules and the
+    // server computes no next-due, so it can NEVER enter the due set —
+    // even with a recent ad-hoc intake on record.
+    const due = deriveDueMedications(
+      [
+        makeMed({
+          id: "prn",
+          schedules: [],
+          nextDueAt: null,
+          lastTakenAt: new Date(now.getTime() - 60 * 60 * 1000).toISOString(),
+          todayEventCount: 1,
+        }),
+        makeMed({ id: "scheduled" }),
+      ],
+      opts,
+    );
+    expect(due.map((m) => m.id)).toEqual(["scheduled"]);
+  });
+
   it("excludes a dose already covered by an actioned intake in its band", () => {
     // Taken 30 minutes ago — inside the open 12:00 band; the in-window
     // suppression (same as the card pill) keeps it out of the due set.

src/components/medications/card-parts/medication-card-body.tsx

@@ -111,6 +111,15 @@ export interface MedicationCardBodyProps {
   /** The open-cycle descriptor, or null when the display block is absent. */
   currentCycle: CurrentCycle | null;
 
+  /**
+   * v1.16.11 (#316) — as-needed (PRN) medication. True suppresses the
+   * compliance block entirely (no bars, no skeleton, no error fallback —
+   * the batched compliance read excludes as-needed medications, so a
+   * skeleton would spin forever) and the open-cycle slot. The next/last
+   * lines carry the "Bei Bedarf" + last-taken presentation instead.
+   */
+  asNeeded?: boolean;
+
   /** "take" | "skip" while the matching request is in flight, else null. */
   intakeLoading: string | null;
   /** Record the displayed dose (the card binds the slot instant). */
@@ -137,6 +146,7 @@ export function MedicationCardBody({
   complianceError = false,
   onRetryCompliance,
   currentCycle,
+  asNeeded = false,
   intakeLoading,
   onRecordIntake,
   children,
@@ -214,6 +224,7 @@ export function MedicationCardBody({
             error fallback (no bars, one notice line + retry) instead of
             sitting on the skeleton forever. */}
         {active &&
+          !asNeeded &&
           (compliance ? (
             <MedicationComplianceBars
               rate7={compliance.rate7}
@@ -232,7 +243,7 @@ export function MedicationCardBody({
             one xs text line on every active card: the descriptor rides the
             compliance query, and a line appearing after the fetch resolved
             used to grow the card and shift the grid row (CLS). */}
-        {active && (
+        {active && !asNeeded && (
           <div className="min-h-4">
             {currentCycle && <MedicationCycleStatus cycle={currentCycle} />}
           </div>

src/components/medications/detail/MedicationDetailTabs.tsx

@@ -136,6 +136,8 @@ export interface MedicationDetailSnapshot {
   startsOn?: string | null;
   endsOn?: string | null;
   oneShot?: boolean;
+  /** v1.16.11 (#316) — as-needed (PRN): no schedules, never due. */
+  asNeeded?: boolean;
   atcCode?: string | null;
   rxNormCode?: string | null;
   /**
@@ -189,6 +191,7 @@ function snapshotToWizardPayload(
     startsOn: med.startsOn ? new Date(med.startsOn) : null,
     endsOn: med.endsOn ? new Date(med.endsOn) : null,
     oneShot: med.oneShot ?? false,
+    asNeeded: med.asNeeded ?? false,
     schedules: med.schedules.map((s) => ({
       id: s.id,
       windowStart: s.windowStart,
@@ -226,6 +229,7 @@ export function MedicationDetailTabs({
 
   const id = medication.id;
   const oneShot = medication.oneShot === true;
+  const asNeeded = medication.asNeeded === true;
   const isGlp1 = !oneShot && medication.treatmentClass === "GLP1";
   const isInjectable = medication.deliveryForm === "INJECTION";
 
@@ -238,9 +242,18 @@ export function MedicationDetailTabs({
   // whatever `?tab=` carries — Injektion is absent for non-injectable
   // medications, so a stale `?tab=injektion` deep-link falls back to the
   // landing tab instead of rendering an empty surface.
+  // v1.16.11 — an as-needed medication has no schedule and never
+  // reminds, so the Zeitplan tab (times editor + reminder card +
+  // plan-history) does not apply and is dropped from the registry; a
+  // stale `?tab=zeitplan` deep-link falls back to the landing tab.
   const availableTabs = useMemo<TabSlug[]>(
-    () => TAB_SLUGS.filter((slug) => slug !== "injektion" || isInjectable),
-    [isInjectable],
+    () =>
+      TAB_SLUGS.filter(
+        (slug) =>
+          (slug !== "injektion" || isInjectable) &&
+          (slug !== "zeitplan" || !asNeeded),
+      ),
+    [isInjectable, asNeeded],
   );
 
   const requestedRaw = searchParams?.get("tab");
@@ -296,7 +309,9 @@ export function MedicationDetailTabs({
         return null;
       }
     },
-    enabled: activeTab === "uebersicht",
+    // v1.16.11 — no compliance read for an as-needed medication (the
+    // section is hidden; there is no rate to fetch).
+    enabled: activeTab === "uebersicht" && !asNeeded,
     staleTime: 30_000,
   });
 
@@ -368,6 +383,7 @@ export function MedicationDetailTabs({
         endsOn={medication.endsOn}
         payload={payload}
         oneShot={oneShot}
+        asNeeded={asNeeded}
         startsOn={medication.startsOn}
       />
 
@@ -407,25 +423,35 @@ export function MedicationDetailTabs({
                 value={
                   !medication.active
                     ? t("medications.detail.uebersicht.pausedHint")
-                    : medication.nextDueAt
-                      ? fmt.dateTime(medication.nextDueAt)
-                      : t("medications.detail.uebersicht.nextDoseNone")
+                    : asNeeded
+                      ? t("medications.detail.uebersicht.nextDoseAsNeeded")
+                      : medication.nextDueAt
+                        ? fmt.dateTime(medication.nextDueAt)
+                        : t("medications.detail.uebersicht.nextDoseNone")
                 }
-                jumpLabel={t("medications.detail.uebersicht.jumpToZeitplan")}
-                onJump={() => onTabChange("zeitplan")}
+                jumpLabel={
+                  asNeeded
+                    ? t("medications.detail.uebersicht.jumpToVerlauf")
+                    : t("medications.detail.uebersicht.jumpToZeitplan")
+                }
+                onJump={() => onTabChange(asNeeded ? "verlauf" : "zeitplan")}
                 dataSlot="uebersicht-next-dose"
               />
-              <StatusRow
-                label={t("medications.detail.uebersicht.reminderLabel")}
-                value={
-                  medication.notificationsEnabled
-                    ? t("medications.detail.uebersicht.reminderOn")
-                    : t("medications.detail.uebersicht.reminderOff")
-                }
-                jumpLabel={t("medications.detail.uebersicht.jumpToZeitplan")}
-                onJump={() => onTabChange("zeitplan")}
-                dataSlot="uebersicht-reminder"
-              />
+              {/* v1.16.11 — as-needed never reminds; the row would only
+                  mislead (the cron skips schedule-less medications). */}
+              {!asNeeded && (
+                <StatusRow
+                  label={t("medications.detail.uebersicht.reminderLabel")}
+                  value={
+                    medication.notificationsEnabled
+                      ? t("medications.detail.uebersicht.reminderOn")
+                      : t("medications.detail.uebersicht.reminderOff")
+                  }
+                  jumpLabel={t("medications.detail.uebersicht.jumpToZeitplan")}
+                  onJump={() => onTabChange("zeitplan")}
+                  dataSlot="uebersicht-reminder"
+                />
+              )}
               {inventoryItems.length > 0 && (
                 <StatusRow
                   label={t("medications.detail.uebersicht.supplyLabel")}
@@ -471,6 +497,7 @@ export function MedicationDetailTabs({
             </ul>
           </MedicationDetailSection>
 
+          {!asNeeded && (
           <MedicationDetailSection
             titleId="medication-uebersicht-compliance-heading"
             title={t("medications.detail.uebersicht.complianceTitle")}
@@ -490,6 +517,7 @@ export function MedicationDetailTabs({
               </p>
             )}
           </MedicationDetailSection>
+          )}
         </TabsContent>
 
         {/* ZEITPLAN — inline edit of the everyday levers: dose times +

src/components/medications/medication-card.tsx

@@ -85,6 +85,13 @@ interface Medication {
    * still takeable" instead of the regular upcoming-intake phrasing.
    */
   nextDueOverdue?: boolean;
+  /**
+   * v1.16.11 (#316) — as-needed (PRN) medication: no schedules, never
+   * due, never reminded, no compliance. The card renders a calm
+   * "Bei Bedarf" marker where next-due normally sits and replaces the
+   * compliance bars with the last-taken oriented presentation.
+   */
+  asNeeded?: boolean;
   schedules: Schedule[];
 }
 
@@ -300,6 +307,15 @@ export function MedicationCard({
     />
   );
 
+  // v1.16.11 — as-needed: a calm marker where next-due normally sits.
+  // No due pill, no overdue escalation, ever (structurally there is no
+  // schedule, so the window status is already null).
+  const asNeededLine = medication.asNeeded ? (
+    <span className="text-muted-foreground" data-slot="medication-as-needed-marker">
+      {t("medications.asNeededMarker")}
+    </span>
+  ) : null;
+
   // The upcoming-intake line value — a day label + window range + optional
   // dose accent. The card owns this VALUE content (a daily med reads as a
   // clock-time window); the structure / labels live in the shared body.
@@ -396,13 +412,14 @@ export function MedicationCard({
             }
           : null
       }
-      doseStatus={doseStatus}
-      nextLine={nextLine}
+      doseStatus={medication.asNeeded ? "upcoming" : doseStatus}
+      nextLine={asNeededLine ?? nextLine}
       lastLine={
         medication.lastTakenAt
           ? formatLastTakenAt(medication.lastTakenAt)
           : null
       }
+      asNeeded={medication.asNeeded === true}
       compliance={
         compliance ? { rate7, rate30, streak, shortDays, longDays } : null
       }

src/components/medications/medication-detail-summary.tsx

@@ -31,6 +31,8 @@ export interface MedicationDetailSummaryProps {
   /** Wizard payload used to derive the plain-language cadence line. */
   payload: MedicationPayload;
   oneShot: boolean;
+  /** v1.16.11 — as-needed (PRN): the cadence line reads "Bei Bedarf". */
+  asNeeded?: boolean;
   startsOn?: string | null;
 }
 
@@ -53,6 +55,7 @@ export function MedicationDetailSummary({
   endsOn,
   payload,
   oneShot,
+  asNeeded = false,
   startsOn,
 }: MedicationDetailSummaryProps) {
   const { t } = useTranslations();
@@ -83,7 +86,9 @@ export function MedicationDetailSummary({
           date: formatters.dateTime(startsOn),
         })
       : t("medications.detail.cadence.oneShotPending")
-    : summariseCadence(hydrateWizardPayload(payload), t, formatters.date);
+    : asNeeded
+      ? t("medications.detail.cadence.asNeeded")
+      : summariseCadence(hydrateWizardPayload(payload), t, formatters.date);
 
   return (
     <div className="space-y-1.5" data-slot="medication-detail-summary">

src/components/medications/medication-table.tsx

@@ -87,6 +87,11 @@ export interface TableMedication {
   todayEventCount?: number;
   nextDueAt?: string | null;
   nextDueOverdue?: boolean;
+  /**
+   * v1.16.11 (#316) — as-needed (PRN): the next-dose cell shows a calm
+   * "Bei Bedarf" marker, the compliance column shows "–".
+   */
+  asNeeded?: boolean;
   /** v1.16.10 — dose-derived stock from the list payload; null = inventory tracking off. */
   stockDosesRemaining?: number | null;
   schedules: TableSchedule[];
@@ -463,7 +468,18 @@ function MedicationTableRowItem({
   let nextCell: React.ReactNode = (
     <span className="text-muted-foreground">–</span>
   );
-  if (medication.active) {
+  if (medication.asNeeded) {
+    // v1.16.11 — a calm marker where next-due normally sits; no due
+    // pill, no overdue escalation, ever.
+    nextCell = (
+      <span
+        className="text-muted-foreground"
+        data-slot="medication-table-as-needed-marker"
+      >
+        {t("medications.asNeededMarker")}
+      </span>
+    );
+  } else if (medication.active) {
     if (medication.nextDueOverdue && nextAt) {
       nextCell = (
         <span className="font-medium text-amber-600 dark:text-amber-400">
@@ -609,7 +625,7 @@ function MedicationTableRowItem({
       </TableCell>
       <TableCell>{statusCell}</TableCell>
       <TableCell className="text-sm">{nextCell}</TableCell>
-      <TableCell>{medication.active ? complianceCell : <span className="text-muted-foreground text-sm">–</span>}</TableCell>
+      <TableCell>{medication.active && !medication.asNeeded ? complianceCell : <span className="text-muted-foreground text-sm">–</span>}</TableCell>
       <TableCell className="text-sm">{stockCell}</TableCell>
       <TableCell>
         {medication.active ? (

src/components/medications/wizard/__tests__/wizard-payload.test.ts

@@ -1036,3 +1036,93 @@ describe("v1.15.18 per-dose windows — encode + hydrate round-trip", () => {
     ]);
   });
 });
+
+// ────────────────────────────────────────────────────────────────────
+// v1.16.11 (#316) — as-needed (PRN) mode
+// ────────────────────────────────────────────────────────────────────
+
+describe("as-needed mode (v1.16.11, #316)", () => {
+  function asNeededPayload(): WizardPayload {
+    return {
+      ...emptyWizardPayload(),
+      mode: "asNeeded",
+      treatmentRow: "painRelief",
+      name: "Ibuprofen",
+      doseAmount: "400",
+      doseUnit: "mg",
+      unitsPerDose: "2",
+    };
+  }
+
+  it("progressIndices walks the one-shot-shaped path (no cadence detail, no times)", () => {
+    expect(progressIndices("asNeeded", "daily")).toEqual([1, 2, 3, 4, 8]);
+  });
+
+  it("buildCreateBody emits asNeeded:true with an EMPTY schedules array", () => {
+    const body = buildCreateBody(asNeededPayload());
+    expect(body.asNeeded).toBe(true);
+    expect(body.oneShot).toBe(false);
+    expect(body.schedules).toEqual([]);
+    // Dose fields stay first-class — they feed inventory consumption.
+    expect(body.dose).toBe("400 mg");
+    expect(body.unitsPerDose).toBe(2);
+    expect(body.category).toBe("PAIN_RELIEF");
+  });
+
+  it("a scheduled payload emits asNeeded:false (no accidental flag bleed)", () => {
+    const body = buildCreateBody(withCadence("daily"));
+    expect(body.asNeeded).toBe(false);
+    expect(body.schedules.length).toBeGreaterThan(0);
+  });
+
+  it("hydrateWizardPayload round-trips an as-needed snapshot back onto the mode", () => {
+    const hydrated = hydrateWizardPayload({
+      id: "m1",
+      name: "Ibuprofen",
+      dose: "400 mg",
+      category: "PAIN_RELIEF",
+      notificationsEnabled: true,
+      startsOn: null,
+      endsOn: null,
+      oneShot: false,
+      asNeeded: true,
+      schedules: [],
+    });
+    expect(hydrated.mode).toBe("asNeeded");
+    // Step 5 pre-selects "Bei Bedarf" via the mode; the placeholder
+    // draft carries it too so the flat mirror stays coherent.
+    expect(hydrated.schedules).toHaveLength(1);
+    expect(hydrated.schedules[0].mode).toBe("asNeeded");
+
+    // Full round-trip: hydrate → encode emits the same wire shape.
+    const body = buildCreateBody(hydrated, "edit");
+    expect(body.asNeeded).toBe(true);
+    expect(body.schedules).toEqual([]);
+    // Edit bodies never round-trip the reminders default (invariant 16).
+    expect(body.notificationsEnabled).toBeUndefined();
+  });
+
+  it("summariseCadence reads the asNeeded key with no times phrase", () => {
+    const t = makeStubT();
+    const line = summariseCadence(asNeededPayload(), t);
+    expect(line).toContain("medications.wizard.summary.cadence.asNeeded");
+    expect(line).not.toContain("medications.wizard.summary.times");
+  });
+
+  it("summariseScheduleDraft reads the asNeeded key with no times phrase", () => {
+    const t = makeStubT();
+    const line = summariseScheduleDraft(
+      { ...emptyWizardPayload().schedules[0], mode: "asNeeded" },
+      t,
+    );
+    expect(line).toContain("medications.wizard.summary.cadence.asNeeded");
+    expect(line).not.toContain("medications.wizard.summary.times");
+  });
+
+  it("validateStep gates: Step 5 passes once the mode is picked; review mirrors Step 4", () => {
+    const p = asNeededPayload();
+    expect(validateStep(p, 5)).toBe(true);
+    expect(validateStep(p, 8)).toBe(true);
+    expect(validateStep({ ...p, mode: null }, 5)).toBe(false);
+  });
+});

src/components/medications/wizard/steps/Step5Cadence.tsx

@@ -8,9 +8,10 @@ import type { WizardPayload } from "../wizard-payload";
 import type { StepProps } from "./Step1Name";
 
 /**
- * The six cadence rows surfaced in Step 5. Each maps to a (mode,
+ * The seven cadence rows surfaced in Step 5. Each maps to a (mode,
  * cadenceKind) decision. "Einmalig" flips the wizard onto the
- * one-shot path; every other row stays recurring.
+ * one-shot path; "Bei Bedarf" (v1.16.11, #316) onto the as-needed
+ * path (no schedule at all); every other row stays recurring.
  */
 type Step5Row =
   | "daily"
@@ -18,7 +19,8 @@ type Step5Row =
   | "everyNWeeks"
   | "monthly"
   | "rolling"
-  | "oneShot";
+  | "oneShot"
+  | "asNeeded";
 
 const STEP5_ROWS: readonly Step5Row[] = [
   "daily",
@@ -27,10 +29,12 @@ const STEP5_ROWS: readonly Step5Row[] = [
   "monthly",
   "rolling",
   "oneShot",
+  "asNeeded",
 ];
 
 function rowFromPayload(payload: WizardPayload): Step5Row | null {
   if (payload.mode === "oneShot") return "oneShot";
+  if (payload.mode === "asNeeded") return "asNeeded";
   if (payload.mode === "recurring") {
     switch (payload.cadence.kind) {
       case "daily":
@@ -108,6 +112,13 @@ function applyRowPick(
     });
     return;
   }
+  if (row === "asNeeded") {
+    // v1.16.11 — as-needed clears schedule configuration: the wizard
+    // emits an empty `schedules` array on save (`buildCreateBody`), so
+    // the cadence value left on the draft is inert.
+    applyPartial({ mode: "asNeeded" });
+    return;
+  }
   const cadenceKind: CadenceKind = row;
   applyPartial({
     mode: "recurring",

src/components/medications/wizard/steps/Step8Summary.tsx

@@ -145,7 +145,11 @@ export function Step8Summary({
           </p>
         )}
 
-        {payload.mode !== "oneShot" && (
+        {/* v1.16.11 — an as-needed medication carries no parallel
+            schedules; the single "Bei Bedarf" card stays as the route
+            back into Step 5 (mirroring the one-shot edit path), but the
+            add affordance is hidden alongside one-shot. */}
+        {payload.mode !== "oneShot" && payload.mode !== "asNeeded" && (
           <button
             type="button"
             onClick={onAddSchedule}
@@ -163,6 +167,9 @@ export function Step8Summary({
         )}
       </div>
 
+      {/* v1.16.11 — an as-needed medication never reminds (no slots),
+          so the reminders toggle is hidden alongside the schedules. */}
+      {payload.mode !== "asNeeded" && (
       <div className="flex items-start justify-between gap-3">
         <div className="space-y-1">
           <Label
@@ -185,8 +192,9 @@ export function Step8Summary({
           aria-label={t("medications.wizard.steps.step8.remindersLabel")}
         />
       </div>
+      )}
 
-      {showNoChannelHint && (
+      {payload.mode !== "asNeeded" && showNoChannelHint && (
         <p
           className="text-muted-foreground text-xs"
           data-slot="wizard-no-channel-hint"

src/components/medications/wizard/wizard-payload.ts

@@ -176,7 +176,7 @@ export function rowFromTreatment(
  */
 export interface ScheduleDraft {
   id?: string;
-  mode: "oneShot" | "recurring" | null;
+  mode: "oneShot" | "recurring" | "asNeeded" | null;
   cadence: CadenceValue;
   subControls: CadenceSubControls;
   timesOfDay: string[];
@@ -237,7 +237,7 @@ export interface WizardPayload {
    */
   allowedInjectionSites: InjectionSiteKey[];
   /** Set in Step 5 — mirrors `schedules[activeScheduleIndex].mode`. */
-  mode: "oneShot" | "recurring" | null;
+  mode: "oneShot" | "recurring" | "asNeeded" | null;
   /** Mirrors `schedules[activeScheduleIndex].cadence`. */
   cadence: CadenceValue;
   /** Mirrors `schedules[activeScheduleIndex].subControls`. */
@@ -402,6 +402,14 @@ export function removeSchedule(
 // ────────────────────────────────────────────────────────────────────
 
 const ONE_SHOT_PATH: readonly number[] = [1, 2, 3, 4, 8];
+/**
+ * v1.16.11 — as-needed (PRN) walks the one-shot shape: picking
+ * "Bei Bedarf" in Step 5 skips the sub-cadence + times steps entirely
+ * (an as-needed medication carries no schedule), landing on the
+ * summary. The dose step stays — dose text + unitsPerDose still feed
+ * inventory consumption.
+ */
+const AS_NEEDED_PATH: readonly number[] = [1, 2, 3, 4, 8];
 const DAILY_PATH: readonly number[] = [1, 2, 3, 4, 5, 7, 8];
 const RECURRING_PATH: readonly number[] = [1, 2, 3, 4, 5, 6, 7, 8];
 
@@ -418,6 +426,7 @@ export function progressIndices(
   cadenceKind: CadenceKind,
 ): readonly number[] {
   if (mode === "oneShot") return ONE_SHOT_PATH;
+  if (mode === "asNeeded") return AS_NEEDED_PATH;
   if (mode === "recurring" && cadenceKind === "daily") return DAILY_PATH;
   return RECURRING_PATH;
 }
@@ -552,6 +561,11 @@ export interface CreateMedicationBody {
   startsOn?: string;
   endsOn?: string;
   oneShot: boolean;
+  /**
+   * v1.16.11 (#316) — as-needed (PRN) medication. True emits an EMPTY
+   * `schedules` array (the route 422s on any entry alongside the flag).
+   */
+  asNeeded: boolean;
   schedules: Array<{
     id?: string;
     windowStart: string;
@@ -675,10 +689,15 @@ export function buildCreateBody(
   // A one-shot medication carries exactly one schedule with no
   // recurrence. We honour the active draft (it carries the times the
   // user picked); the route enforces the one-schedule invariant.
+  // v1.16.11 — an as-needed medication carries NO schedule at all; the
+  // wizard clears the list client-side (the server 422s otherwise).
   const isOneShot = committed.mode === "oneShot";
-  const draftsToEmit = isOneShot
-    ? [committed.schedules[committed.activeScheduleIndex] ?? committed.schedules[0]]
-    : committed.schedules;
+  const isAsNeeded = committed.mode === "asNeeded";
+  const draftsToEmit = isAsNeeded
+    ? []
+    : isOneShot
+      ? [committed.schedules[committed.activeScheduleIndex] ?? committed.schedules[0]]
+      : committed.schedules;
 
   const parsedDosesPerUnit = Number.parseInt(committed.dosesPerUnit, 10);
   const parsedUnitsPerDose = Number.parseInt(committed.unitsPerDose, 10);
@@ -716,6 +735,7 @@ export function buildCreateBody(
       notificationsEnabled: committed.notificationsEnabled,
     }),
     oneShot: isOneShot,
+    asNeeded: isAsNeeded,
     schedules: draftsToEmit.map((draft) => encodeScheduleDraft(draft, isOneShot)),
   };
   if (committed.startsOn) {
@@ -739,6 +759,7 @@ function summaryKeyForDraft(
   sub: CadenceSubControls,
 ): string {
   if (mode === "oneShot") return "oneShot";
+  if (mode === "asNeeded") return "asNeeded";
   switch (cadence.kind) {
     case "daily":
       return "daily";
@@ -856,7 +877,9 @@ export function summariseCadence(
 ): string {
   const cadenceLine = cadenceLineFor(payload, t);
   const timesPhrase =
-    payload.mode !== "oneShot" && payload.timesOfDay.length > 0
+    payload.mode !== "oneShot" &&
+    payload.mode !== "asNeeded" &&
+    payload.timesOfDay.length > 0
       ? t("medications.wizard.summary.times", {
           times: sortTimes(payload.timesOfDay).join(", "),
         })
@@ -890,7 +913,9 @@ export function summariseScheduleDraft(
 ): string {
   const cadenceLine = cadenceLineFor(draft, t);
   const timesPhrase =
-    draft.mode !== "oneShot" && draft.timesOfDay.length > 0
+    draft.mode !== "oneShot" &&
+    draft.mode !== "asNeeded" &&
+    draft.timesOfDay.length > 0
       ? t("medications.wizard.summary.times", {
           times: sortTimes(draft.timesOfDay).join(", "),
         })
@@ -928,6 +953,8 @@ export interface MedicationPayload {
   startsOn: Date | null;
   endsOn: Date | null;
   oneShot: boolean;
+  /** v1.16.11 — as-needed (PRN) flag; hydrates the "Bei Bedarf" mode. */
+  asNeeded?: boolean;
   schedules: Array<{
     id?: string;
     windowStart: string;
@@ -1012,8 +1039,13 @@ export function hydrateWizardPayload(initial: MedicationPayload): WizardPayload
   const base = emptyWizardPayload();
   const parsedDose = parseDoseExpression(initial.dose ?? "");
 
-  const drafts: ScheduleDraft[] =
-    initial.schedules.length > 0
+  // v1.16.11 — an as-needed medication persists ZERO schedules; hydrate
+  // one placeholder draft carrying the asNeeded mode so the flat mirror
+  // and Step-5 selection round-trip (the encode path emits no schedule).
+  const asNeeded = initial.asNeeded === true;
+  const drafts: ScheduleDraft[] = asNeeded
+    ? [{ ...emptyScheduleDraft(), mode: "asNeeded" }]
+    : initial.schedules.length > 0
       ? initial.schedules.map((schedule) =>
           hydrateScheduleDraft(schedule, initial.oneShot),
         )