There have been many security upgrades since 9/11, this is one of them. The REAL ID Act was passed by Congress in 2005 based on the 9/11 Commissions recommendation. Its purpose is to set a minimum security standard for state-issued driver’s licenses and identification (ID) cards. This change is supposed to minimize the use of fraudulent documents submitted by terrorists and illegal aliens in order to obtain driver’s licenses or ID cards. The compliant state-issued licenses and cards will be identified by a star in the upper right corner.
Starting on January 22, 2018, travelers with driver’s licenses or ID cards from non-compliant states and that state does not have an extension, will not be able to use those documents to fly domestically. Starting on October 1, 2020, all driver’s licenses or ID cards used to fly within the US must be REAL ID compliant. Currently, the state of California has received an extension allowing the TSA to accept non-compliant driver’s licenses and ID cards until October 10, 2017. At this writing, it appears the extension keeps states from being deemed as non-compliant (which is the case for Montana, Minnesota, Missouri, and Maine). But of course, the TSA will accept other forms of identification at security check points, that list is below.
Currently, Minnesota and Missouri are non-complaint states. You can keep track of the status of the states and territories (compliant, non-complaint, and with extensions) on this page. Here is a helpful portable fact sheet you can download.
Updated March 31, 2018
All of the United States are either complaint or they have an extension. American Samoa is the only territory that is non-complaint. The state of California's new extension ends on October 10, 2018. The best work-around for Californians, if you don't already have one, is to get your passport/passport card. If you have a valid passport/passport card, consider using it when flying within the United States or from it's territories. (The passport/passport card work-around applies to anyone living in a state or territory that has a extension.)