Your military ID number is the 10-digit DoD ID Number, formally called the Electronic Data Interchange Personal Identifier (EDIPI). It’s printed on the back of your Common Access Card, on the front of a Uniformed Services ID card, and on the third line of current-issue dog tags. The Defense Enrollment Eligibility Reporting System (DEERS) assigns it, and it stays with you for life.
What the DoD ID Number Is
Everyone with a direct relationship to the Department of Defense gets an EDIPI: active-duty service members, reservists, National Guard members, DoD civilians, contractors, retirees, and eligible dependents.1TRICARE Manuals. TRICARE Systems Manual 7950.4-M – Chapter 3 Section 3.1 Beneficiary Identification DEERS assigns the number and uses it as the primary key that ties you to your personnel records, benefits eligibility, and healthcare enrollment.
The number is permanent. It does not change when you PCS, switch components, retire, or separate. DoD systems rely on the EDIPI to keep records aligned across every database that touches your file, so consistency is the whole point.2United States Marine Corps Flagship. Replacement of Social Security Number (SSN) with Department of Defense (DoD) ID on Identification (ID) Tags
Where to Find Your Number
On a Common Access Card
Active-duty members, DoD civilians, and eligible contractors carry a CAC. The 10-digit number is printed on the back of the card, labeled “DoD ID Number.”3Defense Travel Management Office. How to Enter Your DoD ID Number in Your DTS Profile If you’re pulling it from the card’s digital certificate instead, it appears as the last 10 digits in the “CN=” field, after your name.
On a Uniformed Services ID Card
Retirees and dependents carry a USID card. The DoD ID Number is on the front. You’ll also see an 11-digit DoD Benefits Number (DBN) on the back, but that’s a separate identifier TRICARE uses for coverage checks.4Vance Air Force Base – TRICARE. Headed To the Doctor? Bring Proof of Your TRICARE Coverage Your EDIPI is the universal identifier; the DBN exists only for benefits verification.
On Dog Tags
The DoD ID Number replaced the Social Security Number on the third line of identification tags. It’s printed as 10 digits with no hyphens. Older tags with an SSN don’t have to be reissued, but new tags use the EDIPI.2United States Marine Corps Flagship. Replacement of Social Security Number (SSN) with Department of Defense (DoD) ID on Identification (ID) Tags
Online If You Don’t Have the Card
You can look up your DoD ID Number through the ID Card Office Online at idco.dmdc.osd.mil. Sign in with your DS Logon or CAC credentials. The same portal handles ID card appointments and DEERS updates.
How It Differs From Your SSN
For decades the military used the Social Security Number as the service number, and it appeared on ID cards, dog tags, and most personnel documents. The DoD began removing SSNs from family member ID cards in 2008 and phased them out of card barcodes starting around 2012, driven by identity theft concerns.5The United States Army. DoD to Drop Social Security Numbers from ID Cards
Some legacy USID cards still show an SSN. These stay valid through their printed expiration. If your card has an indefinite (“INDEF”) expiration, you can voluntarily swap it for a Next Generation USID card at any RAPIDS office, but the DoD will not force a reissue for the format alone.6CAC.mil. Next Generation Uniformed Services ID Card If your card still carries your SSN, replacing it sooner is worth the trip.
The SSN hasn’t left military life entirely. Pay systems, tax documents, and processes where federal law specifically requires an SSN still use it. For day-to-day identification, base access, and benefits verification, the DoD ID Number is what the systems ask for.
What the Number Is Used For
DEERS and Benefits
DEERS is the master database that determines who qualifies for military benefits, and your EDIPI is the key that opens your record. Enrolling dependents, changing your address, updating your TRICARE plan, or verifying commissary and exchange privileges all run off that number.1TRICARE Manuals. TRICARE Systems Manual 7950.4-M – Chapter 3 Section 3.1 Beneficiary Identification
Healthcare and VA Records
The Military Health System tracks your medical records by DoD ID Number, which keeps your history intact as you move between duty stations and providers. After separation, the VA uses the same identifier. The Veteran Health Identification Card encodes your EDIPI in both its barcode and magnetic stripe, linking VA healthcare enrollment back to your DoD record.7VA.gov. Veteran Health Identification Card (VHIC) Employee Frequently Asked Questions That connection is what lets the VA pull your service medical records without rebuilding your history by hand.
TSA PreCheck
Active-duty service members and DoD civilians receive TSA PreCheck screening at no cost. Your DoD ID Number doubles as your Known Traveler Number (KTN). Enter the 10 digits from the back of your CAC in the KTN field when you book flights or update airline loyalty profiles.8Transportation Security Administration. Free TSA PreCheck for Uniformed Service Members and DOD Civilians It works for official and personal travel. Adult dependents 18 and over who are not DoD-affiliated do not qualify for free PreCheck through the military and must enroll separately.9Transportation Security Administration. TSA PreCheck FAQ
Base Access and Secure Systems
The number verifies your authorization to enter installations, and it’s the credential behind secure portals like milConnect, the Defense Travel System, and branch personnel systems. On a CAC it works together with the embedded chip and your PIN for multi-factor authentication.
If Your ID Is Lost or Stolen
Report a missing card right away. The path depends on which card you carry.
- Common Access Card: contact your command or local security office at your duty station. You can also call Military OneSource at 1-800-342-9647.
- Uniformed Services ID card: report the loss through the RAPIDS self-service portal at idco.dmdc.osd.mil, or call Military OneSource at the same number.
If a dependent is reporting a lost USID card, the sponsor must complete and sign a new DD Form 1172-2 before a replacement can be issued.10USAGov. How to Report a Lost or Stolen Military or Veteran ID Card
If you think your DoD ID Number has been used fraudulently, notify your commanding officer and file an identity theft report with the FTC at IdentityTheft.gov.11BulkOrder.FTC.gov. Identity Theft – Military Personnel and Families: What to Know, What to Do A compromised EDIPI carries less risk than a compromised SSN, but paired with other stolen information it can be used to reach benefits and personal records.
Keeping the Number Protected
The DoD classifies your ID number as Personally Identifiable Information. Multi-factor authentication limits the damage of exposure alone, since most secure systems also require your physical card and a PIN or biometric scan. The number by itself won’t unlock anything sensitive.
Keep physical control of your card. Businesses may ask to see a military ID for a discount, but they cannot legally photocopy or scan it. Photocopying or reproducing a military ID card is prohibited under 18 U.S.C. 701, which covers anyone who manufactures, sells, possesses, or reproduces a government identification card or a close resemblance of one, with penalties of a fine, up to six months in prison, or both.12Office of the Law Revision Counsel. 18 U.S. Code 701 – Official Badges, Identification Cards, Other Insignia Government agencies conducting official business are the only exception.13The United States Army. Photocopying Military, CAC IDs a Violation of Federal Law If a store insists on making a copy, you can point them to that statute. Organizations outside the DoD generally cannot access your EDIPI unless a formal Memorandum of Understanding authorizes the data sharing.