diff --git a/src/features/background-agent/manager.test.ts b/src/features/background-agent/manager.test.ts
index fd6ff75..6bd818c 100644
--- a/src/features/background-agent/manager.test.ts
+++ b/src/features/background-agent/manager.test.ts
@@ -302,6 +302,74 @@ describe("BackgroundManager.getAllDescendantTasks", () => {
   })
 })
 
+describe("BackgroundManager.notifyParentSession - release ordering", () => {
+  test("should unblock queued task even when prompt hangs", async () => {
+    // #given - concurrency limit 1, task1 running, task2 waiting
+    const { ConcurrencyManager } = await import("./concurrency")
+    const concurrencyManager = new ConcurrencyManager({ defaultConcurrency: 1 })
+
+    await concurrencyManager.acquire("explore")
+
+    let task2Resolved = false
+    const task2Promise = concurrencyManager.acquire("explore").then(() => {
+      task2Resolved = true
+    })
+
+    await Promise.resolve()
+    expect(task2Resolved).toBe(false)
+
+    // #when - simulate notifyParentSession: release BEFORE prompt (fixed behavior)
+    let promptStarted = false
+    const simulateNotifyParentSession = async () => {
+      concurrencyManager.release("explore")
+
+      promptStarted = true
+      await new Promise(() => {})
+    }
+
+    simulateNotifyParentSession()
+
+    await Promise.resolve()
+    await Promise.resolve()
+
+    // #then - task2 should be unblocked even though prompt never completes
+    expect(promptStarted).toBe(true)
+    await task2Promise
+    expect(task2Resolved).toBe(true)
+  })
+
+  test("should keep queue blocked if release is after prompt (demonstrates the bug)", async () => {
+    // #given - same setup
+    const { ConcurrencyManager } = await import("./concurrency")
+    const concurrencyManager = new ConcurrencyManager({ defaultConcurrency: 1 })
+
+    await concurrencyManager.acquire("explore")
+
+    let task2Resolved = false
+    concurrencyManager.acquire("explore").then(() => {
+      task2Resolved = true
+    })
+
+    await Promise.resolve()
+    expect(task2Resolved).toBe(false)
+
+    // #when - simulate BUGGY behavior: release AFTER prompt (in finally)
+    const simulateBuggyNotifyParentSession = async () => {
+      try {
+        await new Promise((_, reject) => setTimeout(() => reject(new Error("timeout")), 50))
+      } finally {
+        concurrencyManager.release("explore")
+      }
+    }
+
+    await simulateBuggyNotifyParentSession().catch(() => {})
+
+    // #then - task2 resolves only after prompt completes (blocked during hang)
+    await Promise.resolve()
+    expect(task2Resolved).toBe(true)
+  })
+})
+
 describe("BackgroundManager.pruneStaleTasksAndNotifications", () => {
   let manager: MockBackgroundManager
 
diff --git a/src/features/background-agent/manager.ts b/src/features/background-agent/manager.ts
index 3b33b47..87083aa 100644
--- a/src/features/background-agent/manager.ts
+++ b/src/features/background-agent/manager.ts
@@ -86,9 +86,13 @@ export class BackgroundManager {
         parentID: input.parentSessionID,
         title: `Background: ${input.description}`,
       },
+    }).catch((error) => {
+      this.concurrencyManager.release(model)
+      throw error
     })
 
     if (createResult.error) {
+      this.concurrencyManager.release(model)
       throw new Error(`Failed to create background session: ${createResult.error}`)
     }
 
@@ -345,6 +349,10 @@ export class BackgroundManager {
 
     const taskId = task.id
     setTimeout(async () => {
+      if (task.model) {
+        this.concurrencyManager.release(task.model)
+      }
+
       try {
         const messageDir = getMessageDir(task.parentSessionID)
         const prevMessage = messageDir ? findNearestMessageWithFields(messageDir) : null
@@ -367,10 +375,6 @@ export class BackgroundManager {
       } catch (error) {
         log("[background-agent] prompt failed:", String(error))
       } finally {
-        if (task.model) {
-          this.concurrencyManager.release(task.model)
-        }
-        // Always clean up both maps to prevent memory leaks
         this.clearNotificationsForTask(taskId)
         this.tasks.delete(taskId)
         log("[background-agent] Removed completed task from memory:", taskId)