diff --git a/ddl/migrations/0218_drop_user_balance_history_user_mint_timestamp_idx.sql b/ddl/migrations/0218_drop_user_balance_history_user_mint_timestamp_idx.sql
new file mode 100644
index 00000000..4debe30c
--- /dev/null
+++ b/ddl/migrations/0218_drop_user_balance_history_user_mint_timestamp_idx.sql
@@ -0,0 +1,5 @@
+-- Production pg_stat_user_indexes showed this wide mint index at roughly 78 GB
+-- with zero scans. The API balance-history endpoint filters by user_id and
+-- timestamp only, which is covered by user_balance_history_user_timestamp_idx.
+
+drop index concurrently if exists user_balance_history_user_mint_timestamp_idx;