The TSA clarified that a Costco membership card is not a valid Real ID for airport security checkpoints, despite some travelers' confusion after new Real ID rules took effect.

In addition to Real IDs, passports, passport cards, U.S. Department of Defense IDs and DHS trusted traveler cards are considered acceptable forms of identification at TSA checkpoints. A full list of acceptable forms of identification can be found on the TSA website. The TSA says the list of acceptable IDs is subject to change without notice.