Yes, Corningware can go in the freezer. Corningware material can withstand both extreme cold and heat, making it ideal for use in the freezer. Just be sure to leave some headspace in the dish to allow for contraction as the food freezes. Never cover a hot plate with the storage lid until it has cooled all the way to avoid a thermal shock. And when you're ready to eat, thaw the food in the refrigerator overnight before reheating.