The United States Department of Homeland Security recently announced that, beginning October 1, 2020, there will be new ID requirement for boarding commercial flights—even domestic ones. According to the notice, “you will need a REAL ID-compliant license or another acceptable form of ID, such as a valid passport or US military ID, to fly within the US.”

CNN reports that the REAL ID Act sets new minimum security standards when it comes to producing and issuing state licenses. Licenses produced and issues in states that do not comply with the new regulations will not be accepted by federal agencies.

If you don’t have the right ID on or after October 1, 2020, you won’t get past security. Simple as that.

This has some people worried that severe delays and backups may result, if the information about the new requirements is not adequately communicated to the general public. Indeed, according to Tori Emerson Barnes, executive vice president of public affairs and policy at the U.S. Travel Association, 57 percent of Americans are not aware of the approaching deadline.

“We have real concerns, based on some recent surveys we did, that 99 million Americans do not have any form of REAL ID-compliant identification,” she told CNN.

As of now, 47 states are REAL ID compliant (the hold-outs are New Jersey, Oklahoma and Oregon). However, just 27 percent of Americans have REAL IDs.

If you’re unsure about whether your ID qualifies, look at the upper right hand corner of your ID: if it has a star, it is REAL ID compliant. If it doesn’t, it’s not—and you won’t be able to fly. Below is a list of acceptable ID:

• REAL ID-compliant state driver’s licenses or other state photo identity cards

• US passport

• US passport card

• DHS trusted traveler cards (Global Entry, NEXUS, SENTRI, FAST)

• US Department of Defense ID, including IDs issued to dependents

• Permanent resident card

• Border crossing card

• State-issued Enhanced Driver’s License

• Federally recognized, tribal-issued photo ID

• HSPD-12 PIV card

• Foreign government-issued passport

• Canadian provincial driver’s license or Indian and Northern Affairs Canada card

• Transportation worker identification credential

• US Citizenship and Immigration Services Employment Authorization Card (I-766)

• US Merchant Mariner Credential