All air travelers 18 years old and older will need a REAL ID-compliant driver's license, state-issued enhanced driver's license, or other acceptable form of ID to fly within the U.S., beginning Oct. 1.

The REAL ID-compliant cards are marked with a star in the top right corner of the card.

State-issued enhanced driver's licenses are marked with a flag. The documents will be accepted at the airport security checkpoint when the REAL ID enforcement goes into effect.

The REAL ID Act was passed by Congress back in 2005, and enacted the 9/11 Commission's recommendation that the federal government "set standards for the issuance of sources of identification, such as driver's licenses."