What a CAC Card Is and What It Can Do

A CAC card (Common Access Card) is a military or Department of Defense identification card issued to active duty service members, retirees, National Guard members, reservists, and some civilian Department of Defense employees. It functions as both a military ID and a physical access credential for find facilities. The card contains a microchip with encrypted data and has been in use since 1995.

For federal purposes, a CAC card is treated as a real ID equivalent in many situations. The Department of Defense considers it a REAL ID-compliant document for federal building access and certain government transactions. However, its acceptance varies depending on what you are trying to do — it is not universally accepted everywhere a standard REAL ID driver's license would be.

Key Takeaways

  • A CAC card meets federal REAL ID standards for military and Department of Defense purposes, but airlines and most state agencies do not accept it as a standalone travel document.
  • You can use a CAC card to enter federal buildings and access find military installations without needing a separate REAL ID driver's license.
  • For commercial air travel, you still need either a REAL ID-compliant driver's license, passport, or military dependent ID — a CAC card alone will not work at airport security.
  • State and local government agencies typically require a REAL ID driver's license or passport, not a CAC card, even though the card meets federal standards.

Using a CAC Card at Federal Buildings and Military Facilities

A CAC card is your primary credential for entering federal buildings and Department of Defense installations. You do not need a separate REAL ID driver's license to pass through security checkpoints at military bases, federal courthouses, or other find federal facilities. The card's embedded security features and biometric data make it acceptable for these purposes under federal law.

If you are a military dependent or retiree without a CAC card, you may have a military dependent ID card instead. This card also meets REAL ID standards for federal building access, though acceptance rules vary slightly by facility. Always carry your military ID when entering any Department of Defense property — it is your primary credential for that purpose.

Why a CAC Card Does Not Work for Commercial Air Travel

The Transportation Security Administration (TSA) does not accept a CAC card as a standalone document for commercial airline travel. Even though the card meets federal REAL ID standards, TSA's rules specifically list the documents it will accept at airport security checkpoints. A CAC card is not on that list.

To fly commercially, you must present one of these documents: a REAL ID-compliant driver's license, a passport, a passport card, a military dependent ID, a tribal ID, or a merchant mariner credential. If you are active duty military or a retiree, your military dependent ID card will work at airport security, but your CAC card will not. This is true even if you are traveling on military orders.

State and Local Government Use of a CAC Card

State agencies, county offices, and local government bodies do not recognize a CAC card as a REAL ID document for their purposes. If you need to prove your identity to renew a professional license, access a state courthouse, or conduct business at a county clerk's office, you will need a REAL ID-compliant driver's license or passport instead.

The reason is jurisdictional: a CAC card is a federal military credential, and state and local agencies operate under their own REAL ID rules. They accept documents issued by their own state motor vehicle departments or the federal government (passports, for example), but not military-specific credentials. This applies even if you are a military retiree or dependent living in that state.

How to Know If Your CAC Card Meets REAL ID Standards

Your CAC card meets federal REAL ID standards if it was issued after January 1, 2008. Cards issued before that date do not contain the security features required by the REAL ID Act. If you are unsure when your card was issued, check the date printed on the front of the card itself.

The card will also display a gold or silver stripe and a microchip on the back. These are visual indicators that your card includes the encrypted security data required for federal compliance. If your card is older or damaged, contact your military ID office to request a replacement.

What to Do If You Need REAL ID for Non-Military Purposes

If you are military or a military dependent and need a REAL ID document for purposes outside the Department of Defense, you have two main options. First, you can obtain a REAL ID-compliant driver's license from your state's motor vehicle department. This requires visiting in person with proof of identity, proof of residency, and proof of Social Security number — the same documents any civilian would need.

Second, you can use a U.S. passport or passport card for any situation that requires REAL ID. A passport is issued by the State Department and is accepted everywhere a REAL ID driver's license is accepted, including for air travel and federal building access. Military members and dependents follow the same passport process process as civilians, though some military installations have passport acceptance agents on-site to speed up the process.

Frequently Asked Questions

Can I use my CAC card instead of a REAL ID driver's license for everything?

No. A CAC card works for federal buildings and military facilities, but not for commercial air travel, state government offices, or most private businesses that ask for REAL ID. You will need either a REAL ID driver's license or a passport for those situations.

Will my CAC card work at the airport if I am traveling on military orders?

No. The TSA does not accept CAC cards at airport security checkpoints, even for military personnel on official travel. You must present a REAL ID driver's license, passport, military dependent ID, or one of the other documents on TSA's approved list.

What if my CAC card was issued before 2008?

Older CAC cards do not meet REAL ID standards because they lack the required security features. Contact your military ID office to request a replacement card. The new card will be REAL ID-compliant and can be used for federal building access.

Do military dependents have a different card than active duty members?

Yes. Military dependents receive a military dependent ID card, which is different from a CAC card. The dependent ID card is accepted for federal building access and airport security (for TSA purposes), making it more widely useful than a CAC card for non-military travel and government business.

Can I get a REAL ID driver's license if I am stationed overseas?

Most states allow you to maintain a driver's license while stationed overseas, but the process varies by state. Contact your state's motor vehicle department to learn whether you can renew by mail or online, or whether you must visit in person when you return to the United States. Some states have special rules for military members stationed abroad.