diff --git a/apps/backend/agents/coder.py b/apps/backend/agents/coder.py
index b498ff86f3..e23c94d703 100644
--- a/apps/backend/agents/coder.py
+++ b/apps/backend/agents/coder.py
@@ -190,6 +190,24 @@ def _validate_and_fix_implementation_plan() -> tuple[bool, list[str]]:
         print(f"Continuing build: {highlight(spec_dir.name)}")
         print_progress_summary(spec_dir)
 
+        # Fix for #509: Transition from human_review to in_progress after approval
+        # When continuing a build that was approved, ensure we transition out of human_review
+        plan = load_implementation_plan(spec_dir)
+        if plan and plan.status == "human_review" and plan.planStatus == "review":
+            from review.state import ReviewState
+            review_state = ReviewState.load(spec_dir)
+            if review_state.is_approval_valid(spec_dir):
+                # User approved the plan - transition to in_progress now that execution begins
+                plan.status = "in_progress"
+                plan.planStatus = "in_progress"
+                plan_file = spec_dir / "implementation_plan.json"
+                plan.save(plan_file)
+                print_status("Transitioned from human_review to in_progress after approval", "success")
+            else:
+                # Plan changed after approval or not approved - stay in human_review
+                print_status("Plan requires re-approval before execution can continue", "warning")
+                return
+
         # Check if already complete
         if is_build_complete(spec_dir):
             print_build_complete_banner(spec_dir)
diff --git a/apps/backend/implementation_plan/plan.py b/apps/backend/implementation_plan/plan.py
index 01518f245b..ace67214fd 100644
--- a/apps/backend/implementation_plan/plan.py
+++ b/apps/backend/implementation_plan/plan.py
@@ -167,7 +167,17 @@ def update_status_from_subtasks(self):
         all_subtasks = [s for p in self.phases for s in p.subtasks]
 
         if not all_subtasks:
-            # No subtasks yet - stay in backlog/pending
+            # No subtasks yet - check if this is a failed planning state
+            # Fix for #1149: If status is human_review but no phases/subtasks exist,
+            # planning crashed - reset to backlog instead of preserving invalid state
+            if self.status == "human_review" and not self.phases:
+                # Planning failed - don't show as human_review with Resume button
+                self.status = "backlog"
+                self.planStatus = "pending"
+                self.recoveryNote = "Planning phase failed - no implementation plan created"
+                return
+
+            # Normal case: No subtasks yet - stay in backlog/pending
             if not self.status:
                 self.status = "backlog"
             if not self.planStatus:
diff --git a/apps/frontend/src/main/ipc-handlers/agent-events-handlers.ts b/apps/frontend/src/main/ipc-handlers/agent-events-handlers.ts
index c20fb79dad..7add23404f 100644
--- a/apps/frontend/src/main/ipc-handlers/agent-events-handlers.ts
+++ b/apps/frontend/src/main/ipc-handlers/agent-events-handlers.ts
@@ -282,15 +282,35 @@ export function registerAgenteventsHandlers(
           }
         } else {
           notificationService.notifyTaskFailed(taskTitle, project.id, taskId);
-          persistStatus("human_review");
-          // Include projectId for multi-project filtering (issue #723)
-          safeSendToRenderer(
-            getMainWindow,
-            IPC_CHANNELS.TASK_STATUS_CHANGE,
-            taskId,
-            "human_review" as TaskStatus,
-            projectId
-          );
+          // FIX (ACS-71, #1149): Only set human_review if subtasks exist
+          // If planning crashed before creating phases, don't set human_review
+          // This prevents tasks from getting stuck in "needs resume" state
+          const hasSubtasksOnFail = task.subtasks && task.subtasks.length > 0;
+          if (hasSubtasksOnFail) {
+            persistStatus("human_review");
+            // Include projectId for multi-project filtering (issue #723)
+            safeSendToRenderer(
+              getMainWindow,
+              IPC_CHANNELS.TASK_STATUS_CHANGE,
+              taskId,
+              "human_review" as TaskStatus,
+              projectId
+            );
+          } else {
+            // No subtasks - planning failed before creating phases
+            // Keep task in backlog so user can retry
+            console.warn(
+              `[Task ${taskId}] Process failed but no subtasks created - resetting to backlog`
+            );
+            persistStatus("backlog");
+            safeSendToRenderer(
+              getMainWindow,
+              IPC_CHANNELS.TASK_STATUS_CHANGE,
+              taskId,
+              "backlog" as TaskStatus,
+              projectId
+            );
+          }
         }
       }
     } catch (error) {