diff --git a/ami/jobs/tests/test_jobs.py b/ami/jobs/tests/test_jobs.py
index 7a7f8d5ff..4aab76437 100644
--- a/ami/jobs/tests/test_jobs.py
+++ b/ami/jobs/tests/test_jobs.py
@@ -1215,7 +1215,10 @@ def test_dispatch_mode_filtering(self):
 
     def test_ml_job_dispatch_mode_set_on_creation(self):
         """Test that ML jobs get dispatch_mode set based on project feature flags at creation time."""
-        # Without async flag, ML job should default to sync_api
+        # With the async flag disabled, an ML job is dispatched via sync_api.
+        self.project.feature_flags.async_pipeline_workers = False
+        self.project.save()
+
         sync_job = Job.objects.create(
             job_type_key=MLJob.key,
             project=self.project,
diff --git a/ami/main/migrations/0094_enable_async_pipeline_workers.py b/ami/main/migrations/0094_enable_async_pipeline_workers.py
new file mode 100644
index 000000000..109df3451
--- /dev/null
+++ b/ami/main/migrations/0094_enable_async_pipeline_workers.py
@@ -0,0 +1,59 @@
+"""
+Turn on the ``async_pipeline_workers`` feature flag for every existing project.
+
+This rolls out async ML processing (workers that pull tasks from the NATS queue
+instead of the synchronous push API) to all projects at once. New projects keep
+whatever the model default is at creation time; this migration only updates rows
+that exist at deploy time.
+
+The flag lives inside the ``feature_flags`` JSONB column (a ``ProjectFeatureFlags``
+pydantic model). The update toggles only the one key server-side with ``jsonb_set``
+rather than reading each project's JSON into Python, mutating it, and writing the
+whole value back. Doing it in place leaves the other feature flags untouched even
+if another process changes one of them during the deploy, and it runs as a single
+statement instead of one save per row. The reverse flips the flag back off for
+every project — a blanket disable. It does not restore per-project values from
+before the rollout: some projects may have had the flag enabled individually
+beforehand, so the reverse returns every project to the off state rather than to
+its prior value.
+"""
+
+from django.db import migrations
+
+
+def _set_async_pipeline_workers(apps, schema_editor, *, enabled):
+    Project = apps.get_model("main", "Project")
+    table = schema_editor.connection.ops.quote_name(Project._meta.db_table)
+    with schema_editor.connection.cursor() as cursor:
+        cursor.execute(
+            f"""
+            UPDATE {table}
+            SET feature_flags = jsonb_set(
+                COALESCE(feature_flags, '{{}}'::jsonb),
+                '{{async_pipeline_workers}}',
+                to_jsonb(%s::boolean),
+                true
+            )
+            WHERE COALESCE((feature_flags ->> 'async_pipeline_workers')::boolean, false)
+                  IS DISTINCT FROM %s
+            """,
+            [enabled, enabled],
+        )
+
+
+def enable_async_pipeline_workers(apps, schema_editor):
+    _set_async_pipeline_workers(apps, schema_editor, enabled=True)
+
+
+def disable_async_pipeline_workers(apps, schema_editor):
+    _set_async_pipeline_workers(apps, schema_editor, enabled=False)
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("main", "0093_occurrence_project_score_index"),
+    ]
+
+    operations = [
+        migrations.RunPython(enable_async_pipeline_workers, disable_async_pipeline_workers),
+    ]
diff --git a/ami/main/models.py b/ami/main/models.py
index 8d65888bb..3662b4107 100644
--- a/ami/main/models.py
+++ b/ami/main/models.py
@@ -278,7 +278,7 @@ class ProjectFeatureFlags(pydantic.BaseModel):
     default_filters: bool = False  # Whether to show default filters form in UI
     # Feature flag for jobs to reprocess all images in the project, even if already processed
     reprocess_all_images: bool = False
-    async_pipeline_workers: bool = False  # Whether to use async pipeline workers that pull tasks from a queue
+    async_pipeline_workers: bool = True  # Whether to use async pipeline workers that pull tasks from a queue
 
 
 def get_default_feature_flags() -> ProjectFeatureFlags: