Cooked meatballs can be frozen up to 2 months. Place drained cooked meatballs in a single layer on a cookie sheet. Freeze uncovered about 1 hour. Move meatballs to an airtight freezer container; keep frozen. Thaw meatballs in the fridge overnight, then heat before adding the sauce.
Make the meatballs ahead and keep them warm for parties by serving from a small slow cooker.