Soon there will be 9 states what will require a passport to board a plane.

The nine states are Kentucky, Maine, Minnesota, Missouri, Montana, Oklahoma, Pennsylvania, South Carolina, and Washington.

Each of these states does not currently issue a state ID that lives up to federal ID minimum security requirements, according to the REAL ID Act of 2005.

Each of these states have three months to make changes to their state IDs or drivers licenses so that they meet all the federal government standards. 

If they don't, you'll need to apply for or renew a passport—or remember to take your passport with you—before passing TSA and getting on a commercial airplane to another U.S. city.