diff --git a/.changeset/daring-otters-fly.md b/.changeset/daring-otters-fly.md
new file mode 100644
index 000000000..0ae87f843
--- /dev/null
+++ b/.changeset/daring-otters-fly.md
@@ -0,0 +1,5 @@
+---
+type: Fixed
+pr: 3578
+---
+**`/gsd:plan-phase` now refuses to replan closed phases** — `init.plan-phase` exposes a new `phase_status` field and the workflow short-circuits on `Complete` phases (use `--force` to override; `--reviews` has no override).