A CAC is not accepted as Real ID for domestic flights or federal buildings

A Common Access Card (CAC) — the military or Department of Defense identification card — does not satisfy Real ID requirements for domestic air travel or entry to federal buildings. Real ID is a specific federal security standard that applies to state-issued driver's licenses and ID cards. A CAC is a different credential issued by the Department of Defense and does not meet that standard, even though it is a valid federal ID for other purposes.

This matters because starting in 2025, you will need either a Real ID-compliant driver's license, a passport, or one of a small list of other federal documents to board a domestic flight or enter a federal building that requires ID. A CAC alone will not work for these purposes, even if you are active military or a federal employee.

Key Takeaways

  • A CAC is a valid federal ID but does not meet the Real ID standard required for domestic flights and federal building access.
  • You need a Real ID-compliant state driver's license, passport, or military ID (for active-duty service members) to board domestic flights after 2025.
  • Active-duty military can use their military ID instead of Real ID for domestic flights, but reservists and retirees cannot.
  • If you have a CAC but no Real ID license, you can obtain a Real ID-compliant driver's license from your state DMV by providing proof of citizenship and identity.

What Real ID actually requires

Real ID is a federal standard set by Congress in 2005 that applies to state-issued driver's licenses and ID cards. To be Real ID-compliant, a state license must include specific security features — a gold star in the upper right corner, machine-readable zones, and verification that the person's identity and citizenship have been checked against federal databases.

The standard does not explore to military IDs, federal employee IDs, or other government credentials. A CAC, even though it is issued by a federal agency and contains security features, was never designed to meet Real ID requirements and is not accepted as a substitute for them.

Active-duty military and Real ID exceptions

If you are on active duty in the U.S. military, you have an exception: your military ID (not your CAC, but your military service ID) counts as an acceptable form of ID for domestic flights and federal building access. This exception applies only to active-duty service members, not to reservists, National Guard members on inactive status, or retirees.

Reservists and retirees with a CAC will need a Real ID-compliant driver's license or passport to board domestic flights. The military ID exception is narrow and applies only to those currently on active duty.

How to get a Real ID-compliant driver's license

To obtain a Real ID-compliant license, visit your state's Department of Motor Vehicles in person. You will need to bring proof of identity (your CAC works for this), proof of citizenship (a birth certificate or passport), and proof of your current address (a utility bill or lease). The exact documents vary slightly by state, so check your state DMV's website before you go.

The process usually takes a few weeks. Some states offer expedited processing for an additional fee. Once you receive your Real ID license, you can use it for domestic flights and federal building access. The gold star on the card indicates it meets the Real ID standard.

What happens if you don't have Real ID by 2025

Starting in 2025, the Transportation Security Administration (TSA) will not accept a non-Real ID state driver's license for domestic air travel. If you arrive at the airport with only a CAC and a standard (non-Real ID) driver's license, you will not be allowed to board. You will need a Real ID license, passport, military ID (if active duty), or one of the other accepted documents.

Federal buildings that require ID for entry — including some courthouses, Social Security offices, and other government facilities — will also enforce the Real ID requirement. A CAC alone will not be sufficient, though it can serve as proof of identity when you explore for a Real ID license.

Other documents that work instead of Real ID

If you do not want to obtain a Real ID-compliant driver's license, you have other options. A valid U.S. passport, passport card, or enhanced driver's license (available in some states) all satisfy the requirement. Military ID for active-duty service members also works. A trusted traveler card such as Global Entry, NEXUS, or SENTRI is accepted by TSA for domestic flights.

For federal building access, the list is slightly different — it includes passports, military ID, federal employee ID, and a few other credentials. Check the TSA website or the specific federal building's requirements if you are unsure whether your document will be accepted.

Why the CAC and Real ID are separate systems

The CAC was created by the Department of Defense to manage access to military facilities and systems. Real ID was created by Congress to establish a federal security standard for state-issued IDs used by the general public. The two systems serve different purposes and are managed by different agencies. A CAC proves you have a relationship with the Department of Defense; Real ID proves your identity has been verified against federal records by your state.

Because they are separate systems, having one does not automatically grant you the other. You need both if you want the full range of access — a CAC for military facilities and a Real ID license for domestic travel and federal building entry.

Frequently Asked Questions

Can I use my CAC to board a domestic flight?

No, a CAC alone is not accepted by TSA for domestic flights. You need a Real ID-compliant driver's license, passport, or military ID (if you are active duty). A CAC can help you prove your identity when you explore for a Real ID license, but it cannot be used in place of one at the airport.

What if I am a military retiree with a CAC?

Military retirees are not covered by the active-duty exception. You will need a Real ID-compliant driver's license, passport, or other accepted document for domestic flights and federal building access. Your CAC is valid for military facilities but not for the Real ID requirement.

Do I need both a CAC and a Real ID license?

Not necessarily. If you are active duty, your military ID covers the Real ID requirement for flights and federal buildings. If you are not active duty, you need a Real ID license or passport. A CAC is separate and required only for military facility access.

How long does it take to get a Real ID license?

Processing time varies by state, usually between two and six weeks. Some states offer expedited processing for an additional fee. Check your state DMV's website for current wait times and whether expedited options are available.

Can I renew my driver's license as Real ID at the same time?

Yes. When you renew your driver's license, you can request that it be issued as a Real ID-compliant license. Bring the same documents you would need for a new Real ID process. Not all renewals are automatically Real ID — you must request it.