A federally approved passport is an acceptable alternative to a Real ID for air travel within the United States. Travelers without a Real ID may undergo additional identity verification by the TSA.

Flying domestically in the United States without a REAL ID-compliant driver’s license or other acceptable identification ...

Since May travelers on domestic flights in the U.S. have needed a Real ID-compliant license to pass through airport security. If you still haven't upgraded and plan to fly, you could be stopped from ...