diff --git a/features/legacy_migrator_coverage.feature b/features/legacy_migrator_coverage.feature
index 0edec1c76..9eb9ca743 100644
--- a/features/legacy_migrator_coverage.feature
+++ b/features/legacy_migrator_coverage.feature
@@ -203,4 +203,10 @@ Feature: Legacy Data Migrator Coverage
   Scenario: Handle file system errors during backup
     Given I have a legacy project with read-only JSON files
     When I run the legacy data migration
-    Then the migration should handle backup errors gracefully
\ No newline at end of file
+    Then the migration should handle backup errors gracefully
+  Scenario: get_all_for_project is called only once for multiple plans
+    Given I have a legacy project with multiple plans to migrate efficiently
+    When I run the legacy data migration with query tracking
+    Then get_all_for_project should be called exactly once
+    And the migration should return true
+    And all plans should be migrated correctly
diff --git a/features/steps/legacy_migrator_steps.py b/features/steps/legacy_migrator_steps.py
index d33a79e20..55a7bb213 100644
--- a/features/steps/legacy_migrator_steps.py
+++ b/features/steps/legacy_migrator_steps.py
@@ -1012,3 +1012,76 @@ def step_check_backup_error_handling(context: Context) -> None:
     """Check that migration handled backup errors gracefully."""
     # The migration may fail or succeed, but shouldn't crash
     assert context.migration_result in [True, False]
+
+
+@given("I have a legacy project with multiple plans to migrate efficiently")
+def step_create_project_multiple_plans_efficiency(context: Context) -> None:
+    """Create a legacy project with multiple plans for efficiency testing."""
+    project_dir = context.temp_dir / "efficiency_test"
+    project_dir.mkdir(exist_ok=True)
+
+    cleveragents_dir = project_dir / ".cleveragents"
+    cleveragents_dir.mkdir(exist_ok=True)
+
+    (cleveragents_dir / "project.name").write_text("efficiency_test")
+
+    # Create multiple plans to ensure the loop runs more than once
+    plans_data = {
+        "plan_alpha": {"prompt": "Alpha plan", "status": "pending", "current": False},
+        "plan_beta": {"prompt": "Beta plan", "status": "built", "current": False},
+        "plan_gamma": {"prompt": "Gamma plan", "status": "applied", "current": True},
+        "plan_delta": {"prompt": "Delta plan", "status": "pending", "current": False},
+    }
+    (cleveragents_dir / "plans.json").write_text(json.dumps(plans_data))
+    (cleveragents_dir / "current").write_text("plan_gamma")
+
+    context.project_path = project_dir
+
+
+@when("I run the legacy data migration with query tracking")
+def step_run_migration_with_tracking(context: Context) -> None:
+    """Run migration while tracking how many times get_all_for_project is called."""
+    # Find the plans repository class to patch at the class level
+    with context.unit_of_work.transaction() as ctx:
+        repo_class = type(ctx.plans)
+
+    call_tracker = {"count": 0}
+    original_repo_method = repo_class.get_all_for_project
+
+    def tracking_method(self, project_id):
+        call_tracker["count"] += 1
+        return original_repo_method(self, project_id)
+
+    repo_class.get_all_for_project = tracking_method
+    try:
+        migrator = LegacyDataMigrator(context.unit_of_work)
+        context.migration_result = migrator.migrate_project_data(context.project_path)
+    finally:
+        repo_class.get_all_for_project = original_repo_method
+
+    context.get_all_for_project_call_count = call_tracker["count"]
+
+
+@then("get_all_for_project should be called exactly once")
+def step_check_get_all_called_once(context: Context) -> None:
+    """Verify get_all_for_project was called exactly once (not once per plan)."""
+    call_count = context.get_all_for_project_call_count
+    assert call_count == 1, (
+        f"Expected get_all_for_project to be called exactly once, "
+        f"but it was called {call_count} times. "
+        f"This indicates an N+1 query pattern is still present."
+    )
+
+
+@then("all plans should be migrated correctly")
+def step_check_all_plans_migrated(context: Context) -> None:
+    """Verify all plans from the efficiency test were migrated."""
+    with context.unit_of_work.transaction() as ctx:
+        project = ctx.projects.get_by_name("efficiency_test")
+        assert project is not None, "Project should have been created"
+        plans = ctx.plans.get_all_for_project(project.id)
+        plan_names = {p.name for p in plans}
+        expected_names = {"plan_alpha", "plan_beta", "plan_gamma", "plan_delta"}
+        assert plan_names == expected_names, (
+            f"Expected plans {expected_names}, got {plan_names}"
+        )
diff --git a/src/cleveragents/infrastructure/database/legacy_migrator.py b/src/cleveragents/infrastructure/database/legacy_migrator.py
index 2e34d2ec3..7e5309860 100644
--- a/src/cleveragents/infrastructure/database/legacy_migrator.py
+++ b/src/cleveragents/infrastructure/database/legacy_migrator.py
@@ -101,9 +101,11 @@ class LegacyDataMigrator:
                     with open(plans_json) as f:
                         plans_data = json.load(f)
 
+                    # Fetch all existing plans once before the loop to avoid
+                    # N+1 database queries (one query per plan iteration).
+                    all_plans = ctx.plans.get_all_for_project(project.id)
                     for plan_name, plan_info in plans_data.items():
                         # Check if plan already exists
-                        all_plans = ctx.plans.get_all_for_project(project.id)
                         existing_plan = next(
                             (p for p in all_plans if p.name == plan_name), None
                         )