diff --git a/apps/backend/prisma/migrations/20250820175830_grant_internal_users_team_admin/migration.sql b/apps/backend/prisma/migrations/20250820175830_grant_internal_users_team_admin/migration.sql
new file mode 100644
index 000000000..0a3806d9f
--- /dev/null
+++ b/apps/backend/prisma/migrations/20250820175830_grant_internal_users_team_admin/migration.sql
@@ -0,0 +1,22 @@
+-- Grant team_admin permission to all users in the "internal" project for all teams they belong to
+INSERT INTO "TeamMemberDirectPermission" ("id", "tenancyId", "teamMemberId", "permissionDbId", "createdAt", "updatedAt")
+SELECT 
+    gen_random_uuid() AS "id",
+    tm."tenancyId",
+    tm."teamMemberId",
+    p."dbId" AS "permissionDbId",
+    CURRENT_TIMESTAMP AS "createdAt",
+    CURRENT_TIMESTAMP AS "updatedAt"
+FROM "TeamMember" tm
+INNER JOIN "ProjectUser" pu ON tm."tenancyId" = pu."tenancyId" AND tm."projectUserId" = pu."projectUserId"
+INNER JOIN "Project" proj ON pu."tenancyId" = proj."tenancyId" AND pu."projectId" = proj."id"
+INNER JOIN "Permission" p ON p."projectConfigId" = proj."configId" AND p."id" = 'team_admin' AND p."scope" = 'TEAM'
+WHERE proj."id" = 'internal'
+    AND NOT EXISTS (
+        -- Don't create duplicate permissions
+        SELECT 1 
+        FROM "TeamMemberDirectPermission" tmdp 
+        WHERE tmdp."tenancyId" = tm."tenancyId" 
+            AND tmdp."teamMemberId" = tm."teamMemberId" 
+            AND tmdp."permissionDbId" = p."dbId"
+    );
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