Cooked turkey breasts will last in the fridge 3-4 days if stored in an airtight container (if you don't have constantly hungry teens!) You can also freeze it for up to 2-3 months. If you ever notice that the turkey breasts have become slimy or smell bad, then they aren't good anymore. Otherwise, you can reheat it in the microwave, oven, or even in the skillet with a little oil. Just heat it until it's hot then serve.