diff --git a/src/resources/extensions/gsd/auto-dispatch.ts b/src/resources/extensions/gsd/auto-dispatch.ts
index 1a9313496..942c98714 100644
--- a/src/resources/extensions/gsd/auto-dispatch.ts
+++ b/src/resources/extensions/gsd/auto-dispatch.ts
@@ -93,14 +93,22 @@ function missingSliceStop(mid: string, phase: string): DispatchAction {
 /**
  * Check for milestone slices missing SUMMARY files.
  * Returns array of missing slice IDs, or empty array if all present or DB unavailable.
+ *
+ * Excludes skipped slices (intentionally summary-less) and legacy-complete
+ * slices whose DB status is authoritative even without on-disk SUMMARY (#3620).
  */
 function findMissingSummaries(basePath: string, mid: string): string[] {
   if (!isDbAvailable()) return [];
-  const sliceIds = getMilestoneSlices(mid).map(s => s.id);
-  return sliceIds.filter(sid => {
-    const summaryPath = resolveSliceFile(basePath, mid, sid, "SUMMARY");
-    return !summaryPath || !existsSync(summaryPath);
-  });
+  const slices = getMilestoneSlices(mid);
+  // Skipped slices never produce SUMMARYs; legacy-complete slices may lack them
+  const CLOSED_STATUSES = new Set(["skipped", "complete", "done"]);
+  return slices
+    .filter(s => !CLOSED_STATUSES.has(s.status))
+    .filter(s => {
+      const summaryPath = resolveSliceFile(basePath, mid, s.id, "SUMMARY");
+      return !summaryPath || !existsSync(summaryPath);
+    })
+    .map(s => s.id);
 }
 
 // ─── Rewrite Circuit Breaker ──────────────────────────────────────────────
diff --git a/src/resources/extensions/gsd/tests/find-missing-summaries-closed.test.ts b/src/resources/extensions/gsd/tests/find-missing-summaries-closed.test.ts
new file mode 100644
index 000000000..a0d0d70b0
--- /dev/null
+++ b/src/resources/extensions/gsd/tests/find-missing-summaries-closed.test.ts
@@ -0,0 +1,48 @@
+/**
+ * Regression test for #3669 — findMissingSummaries skips closed slices
+ *
+ * When a slice has status "skipped", "complete", or "done", it should be
+ * excluded from the missing-summary check because closed slices intentionally
+ * lack SUMMARY files (or their DB status is authoritative).
+ *
+ * This is a structural verification test — it reads the source to confirm the
+ * CLOSED_STATUSES guard exists at the filter site.
+ */
+
+import { describe, test } from 'node:test';
+import assert from 'node:assert/strict';
+import { readFileSync } from 'node:fs';
+import { fileURLToPath } from 'node:url';
+import { dirname, join } from 'node:path';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = dirname(__filename);
+
+const source = readFileSync(join(__dirname, '..', 'auto-dispatch.ts'), 'utf-8');
+
+describe('findMissingSummaries closed-status exclusion (#3669)', () => {
+  test('CLOSED_STATUSES set includes skipped, complete, and done', () => {
+    // The source must define a CLOSED_STATUSES set with all three statuses
+    assert.match(source, /CLOSED_STATUSES.*=.*new Set\(/,
+      'CLOSED_STATUSES set should be defined');
+    assert.match(source, /"skipped"/, 'CLOSED_STATUSES should include "skipped"');
+    assert.match(source, /"complete"/, 'CLOSED_STATUSES should include "complete"');
+    assert.match(source, /"done"/, 'CLOSED_STATUSES should include "done"');
+  });
+
+  test('filter uses CLOSED_STATUSES.has() to exclude closed slices', () => {
+    assert.match(source, /CLOSED_STATUSES\.has\(s\.status\)/,
+      'filter should call CLOSED_STATUSES.has(s.status)');
+  });
+
+  test('findMissingSummaries function exists', () => {
+    assert.match(source, /function findMissingSummaries\(/,
+      'findMissingSummaries function should be defined');
+  });
+
+  test('filter is negated (excludes closed, keeps open)', () => {
+    // The filter should use !CLOSED_STATUSES.has() to exclude closed slices
+    assert.match(source, /!CLOSED_STATUSES\.has\(s\.status\)/,
+      'filter should negate CLOSED_STATUSES.has() to exclude closed slices');
+  });
+});
diff --git a/src/resources/extensions/gsd/tests/integration/state-machine-edge-cases.test.ts b/src/resources/extensions/gsd/tests/integration/state-machine-edge-cases.test.ts
index e8abe3d94..db7b992c8 100644
--- a/src/resources/extensions/gsd/tests/integration/state-machine-edge-cases.test.ts
+++ b/src/resources/extensions/gsd/tests/integration/state-machine-edge-cases.test.ts
@@ -920,8 +920,10 @@ describe("completion and verification failures", () => {
     base = createFullFixture();
     openDatabase(join(base, ".gsd", "gsd.db"));
     insertMilestone({ id: "M001", title: "Active", status: "active" });
-    insertSlice({ id: "S01", milestoneId: "M001", title: "First", status: "complete" });
-    insertSlice({ id: "S02", milestoneId: "M001", title: "Second", status: "complete" });
+    // Use "pending" status — closed slices (complete/done/skipped) are
+    // excluded from SUMMARY checks per #3620.
+    insertSlice({ id: "S01", milestoneId: "M001", title: "First", status: "pending" });
+    insertSlice({ id: "S02", milestoneId: "M001", title: "Second", status: "pending" });
     // No S01-SUMMARY.md or S02-SUMMARY.md on disk
 
     const ctx = buildDispatchCtx(base, "M001", {