A CAC is not a Real ID, but it works for some of the same purposes

A Common Access Card (CAC) is a military identification card issued by the Department of Defense to active-duty service members, retirees, and their families. It is not a Real ID—which is a specific federal security standard for state-issued driver's licenses and ID cards. However, a CAC does serve as a valid federal ID for certain transactions, which can create confusion about what it actually is and where you can use it.

The key difference: Real ID is a security standard that state DMVs must meet when issuing driver's licenses and ID cards. A CAC is a separate credential issued by the military. While both are federal IDs, they come from different agencies and follow different rules. A CAC will not satisfy a Real ID requirement for domestic air travel or entry to federal buildings, but it does work as an ID for some other federal purposes.

Key Takeaways

  • A CAC is a military ID card, not a Real ID, and the two are not interchangeable for federal requirements.
  • You cannot use a CAC instead of a Real ID-compliant driver's license for domestic air travel.
  • A CAC does work as a federal ID for accessing military installations, federal courthouses, and some government offices.
  • If you have a CAC but need to fly domestically, you will also need either a Real ID driver's license, passport, or other accepted federal ID.

What Real ID actually requires

Real ID is a federal security standard set by Congress in 2005. It requires state DMVs to verify your identity documents more thoroughly and issue driver's licenses and ID cards that meet specific security features—like machine-readable zones and holograms. Starting in May 2025, you will need a Real ID-compliant driver's license or another accepted federal ID to board a domestic flight or enter certain federal buildings.

The Real ID standard applies only to state-issued IDs. Military credentials like the CAC, passport cards, and military dependent IDs are separate federal documents and do not need to meet the Real ID standard because they are not state IDs. However, they may still be accepted for some of the same purposes—but not all.

Where a CAC works as a federal ID

A CAC is accepted as a valid federal ID for accessing military installations, federal courthouses, and many federal office buildings. If you are a service member, retiree, or military family member with a CAC, you can use it to enter these facilities without needing a Real ID driver's license. The CAC proves your identity and your authorization to be on military property.

A CAC also works for some civilian purposes. Banks, government agencies, and other institutions may accept it as proof of identity. However, acceptance varies by institution, so you should not assume a CAC will work everywhere a Real ID would. Always ask ahead if you are unsure whether a specific organization will take a CAC.

Where a CAC does not work

A CAC will not work for domestic air travel. The Transportation Security Administration (TSA) requires a Real ID-compliant driver's license, passport, passport card, military dependent ID, or other specific federal ID for boarding a domestic flight. A CAC is not on that list. If you have a CAC but no Real ID driver's license, you will need to bring your passport or another accepted ID to the airport.

Similarly, a CAC does not satisfy Real ID requirements for entering federal buildings that are not military installations. Some federal courthouses and office buildings may accept a CAC as a courtesy, but they are not required to, and policies vary by location. If you need to enter a federal building and are unsure whether your CAC will be accepted, contact the building's security office ahead of time.

What to do if you have a CAC but need Real ID compliance

If you have a CAC and need to fly domestically or enter a federal building that requires Real ID, bring your passport or passport card instead. These are federal IDs that satisfy Real ID requirements and are accepted by TSA and federal building security. You do not need to get a Real ID driver's license if you have a passport.

If you prefer to use a driver's license for everyday ID, you will need to visit your state DMV and request a Real ID-compliant license. You will need to bring documents that prove your identity, Social Security number, and address. The process is the same as renewing a license, though some states charge a small fee for the Real ID upgrade. Check your state DMV website for the specific documents they require.

Military dependent IDs and Real ID

If you are a military family member with a military dependent ID card (not a CAC), that card may work for some purposes a CAC does. Military dependent IDs are also federal credentials and are accepted for entering military installations. However, like the CAC, a military dependent ID is not a Real ID and will not work for domestic air travel.

Military family members who need a Real ID-compliant ID for travel or federal building access should use a passport or passport card, or obtain a Real ID driver's license from their state DMV. The rules are the same as for CAC holders.

Frequently Asked Questions

Can I use my CAC to fly on a domestic flight?

No. The TSA does not accept a CAC for domestic air travel. You will need a Real ID-compliant driver's license, passport, passport card, or other accepted federal ID. If you have a passport, bring that instead of getting a Real ID driver's license.

Is a CAC the same thing as a Real ID?

No. A CAC is a military credential issued by the Department of Defense. Real ID is a federal security standard for state-issued driver's licenses and ID cards. They are different documents from different agencies, though both are federal IDs.

Can I use a CAC to enter a federal courthouse?

It depends on the courthouse. Some federal courthouses accept a CAC as a valid ID, while others may not. Contact the courthouse's security office before you go to confirm whether your CAC will be accepted.

What if I don't have a Real ID driver's license or passport?

You can visit your state DMV and request a Real ID-compliant driver's license. Bring documents that prove your identity, Social Security number, and address. Some states charge a fee for the upgrade. Check your state DMV website for the specific documents required.

Do military family members need a Real ID?

Military family members with dependent ID cards face the same Real ID requirements as anyone else. If you need to fly domestically or enter federal buildings, you will need a Real ID driver's license, passport, or other accepted federal ID. A military dependent ID card is not a Real ID.