diff --git a/backend/infra/migrations/009_add_subscription_tier.sql b/backend/infra/migrations/009_add_subscription_tier.sql
index 92ce8fd..8d576a0 100644
--- a/backend/infra/migrations/009_add_subscription_tier.sql
+++ b/backend/infra/migrations/009_add_subscription_tier.sql
@@ -1 +1,8 @@
 ALTER TABLE users ADD COLUMN IF NOT EXISTS subscription_tier VARCHAR(20) DEFAULT 'free';
+
+-- Existing active/trialing subscribers were on the single paid plan,
+-- which is now the "premium" tier. Backfill them so they aren't downgraded.
+UPDATE users
+SET subscription_tier = 'premium'
+WHERE subscription_status IN ('active', 'trialing')
+  AND stripe_subscription_id IS NOT NULL;