In 2026, the TSA continues to classify milk for toddlers as a "medically necessary liquid," meaning it is explicitly exempt from the standard 3.4-ounce (100ml) rule. You are allowed to bring a "reasonable quantity" of cow's milk, breast milk, or formula in your carry-on bag, regardless of whether your child is traveling with you. However, these items must be declared to the TSA officer at the start of the screening process. In 2026, many airports have implemented advanced Bottle Liquid Scanners that can verify the contents without the need to open the container, which helps maintain the sterility of the milk. If you are carrying frozen milk, ice packs or gel packs are also permitted, even if they have partially melted. It is highly recommended to pack these liquids in clear, translucent bottles rather than opaque bags to speed up the process. Always arrive 20 minutes earlier than usual to account for the secondary manual screening that these items often trigger to ensure the safety of the aircraft cabin.