One of the great things about meatballs is you can freeze them uncooked or cooked! According to the USDA, uncooked ground meat is freezer-safe for up to three to four months, and cooked ground beef is safe for two to three months. To freeze this dish, place the meatballs and gravy in an airtight freezer-safe container. Freeze up to 3 months. Thaw in the refrigerator overnight, then reheat, thinning the sauce with water if necessary.