(NEXSTAR) — It’s starting to warm up, which means the spring break and summer vacation travel seasons are nearly upon us. Without the necessary ID, however, you may find yourself grounded at the airport.

Come early May, you will need a REAL ID-compliant ID (which you may already have) to board a domestic flight. (It will also be necessary if you are visiting certain federal facilities or entering a nuclear power plant, but we’ll focus on the air travel part for now.)

Once the REAL ID requirement kicks in, federal agencies like TSA will be prohibited from accepting state-issued IDs that do not meet the necessary standards.

Congress passed the REAL ID Act in 2005 in light of the 9/11 terrorist attacks, instituting a national minimum requirement for state driver’s licenses and ID cards. States must now at least require proof of your legal name, date of birth, Social Security number, legal residency, and two forms verifying your address before issuing a driver’s license or ID card.

Before stressing about having to visit the DMV for a new ID, check your wallet: many states have been issuing REAL ID-compliant IDs for years, which means there is a good chance you already have one. If there is a star on your ID, you have a REAL ID.

If you do need a REAL ID, the process should be relatively simple. You’ll need documentation that shows your full legal name, your date of birth, your Social Security number, two proofs of address for your principal residence, and your lawful status.

In most states, your birth certificate and your Social Security card (or, in some cases, just the number), plus a bill and a pay stub, could satisfy requirements. Your state may require additional details, so be sure to check with local authorities, like the Department of Motor Vehicles, to confirm the necessary documentation needed to obtain a REAL ID.

The REAL ID deadline is May 7. Once the deadline passes, if you do not have a REAL ID, you may need to provide another form of identification, like a U.S. passport or military ID, to board a plane.

REAL IDs are optional. You will not need a REAL ID to drive, vote, apply for federal benefits like Social Security, enter a federal facility that otherwise does not require an ID (like a post office), go to a hospital, or “participate in law enforcement proceedings or investigations,” like jury duty.

It is worth noting that REAL IDs will largely only impact your domestic air travel. They cannot be used to cross into Mexico or Canada, and you will still need a passport for international travel, plus any relevant visas.