In short
A federally-compliant US driver license required for domestic air travel starting May 2025.
Real ID is a federally-compliant driver license format that meets the 2005 REAL ID Act's identity verification standards. From May 2025, you'll need a Real ID (or a passport) to fly domestically in the US.
Real IDs are marked with a star in the upper corner. Get one when you renew your driver license — bring proof of identity, Social Security number, and two proofs of address.