diff --git a/UAT_PLAYBOOK.md b/UAT_PLAYBOOK.md
index cb02d20..d5887c6 100644
--- a/UAT_PLAYBOOK.md
+++ b/UAT_PLAYBOOK.md
@@ -21,6 +21,14 @@ GroomBook API is a Hono-based REST service (TypeScript/Node.js) powering the pet
 
 ## Test Cases
 
+### 4.0 Health Check
+
+| # | Scenario | Steps | Expected |
+|---|----------|-------|----------|
+| TC-API-0.1 | Unauthenticated health check | GET /api/health | 200 OK, `{"status":"ok"}` |
+
+> **Note (GRO-1544):** Health endpoint registered on `api` basePath before auth middleware at `/api/health`. The old path `/health` was incorrect (routed to web pod via HTTPRoute `/*` rule).
+
 ### 4.1 Authentication
 
 | # | Scenario | Steps | Expected |