The REAL ID Act of 2005 was a counterterrorism measure adopted following 9/11 that requires States to issue driver licenses with additional security features. These new driver licenses will be required to board commercial flights beginning January 22, 2018.
https://www.tsa.gov/sites/default/files/resources/realid_factsheet.pdf
Many States have already complied, and a significant number have filed for – and received – an extension into the Fall of 2018. To determine the current status of your state, click on the DHS link below.
Travelers with a driver’s license that has been issued by a State that is compliant with REAL ID (or those who hold residency in a State that has been issued an extension) will be able to use their driver’s license to transit airport/TSA security after January 22, 2018. However, if your ID is from one of the few States that is not yet compliant, you may wish to consider getting another form of REAL ID compliant identification (noted in the fact sheet link above).
Questions can be sent directly to the Department of Homeland Security at realid@hq.dhs.gov