As of May 7, 2025, anyone 18 or older will need to present either a passport or a REAL ID to fly domestically and get in a federal building.
In most states, REAL IDs have a star in the top right corner. In California, it's marked with a golden bear and a star.
To get it, you'll need proof of social security, two proofs of residency and proof of status such as a passport, a birth certificate or permanent resident card.
You'll still need a passport to travel internationally.