What Is a Military Service Number and How to Find Yours

A military service number is the unique numeric identifier the U.S. armed forces assigned to each service member from 1918 through the early 1970s to track enlistment, assignments, pay, and medical care. If you served before the switch to Social Security Numbers, or you’re researching a relative who did, your original number appears in Block 3 of the DD Form 214 and can be retrieved from the National Archives when the form isn’t available.

When Service Numbers Were Used

The Army began assigning service numbers to enlisted personnel in February 1918. Before that, the military identified people by name, rank, and unit, which broke down whenever two soldiers shared a name. Each branch developed its own numbering conventions, with different digit lengths, prefix letters, and series ranges for officers, enlisted members, reservists, and National Guard personnel. When the Air Force separated from the Army in 1947, it carried forward a similar structure with its own letter prefixes.

The changeover to Social Security Numbers happened on a staggered schedule. The Army and Air Force switched on July 1, 1969. The Navy and Marine Corps followed on January 1, 1972, and the Coast Guard on October 1, 1974.¹ If you served during or after your branch’s cutover date, your SSN effectively became your service number.

Because SSNs on ID cards, dog tags, and forms created an identity-theft risk, the Department of Defense began replacing them on all DoD identification cards in June 2011 with a 10-digit DoD ID Number, formally called the Electronic Data Interchange Personal Identifier (EDIPI).²³ If you’re currently serving or recently separated, that 10-digit number appears on your Common Access Card or Uniformed Services ID.

Where to Look First

The DD Form 214, officially the Certificate of Release or Discharge from Active Duty, is the single most useful document. Block 3 contains either your original service number or your Social Security Number, depending on when you served.⁴

If you don’t have your DD 214 in hand, the number may also appear on:

Enlistment or induction papers signed when you entered service.
Older military ID cards issued before the SSN and DoD ID transitions.
Discharge papers predating the DD 214, which used different formats but carried the service number.
Medical and health records from military hospitals, which often reference the service number as a patient identifier.

If none of these documents are available, the National Archives can retrieve the number from your Official Military Personnel File.

How to Request Your Records From the National Archives

The National Personnel Records Center (NPRC) in St. Louis holds the official personnel files. Most veterans and their next of kin can get free copies of the DD Form 214 and other records from the OMPF.⁴ There are two ways to file the request.

Online Through eVetRecs

The fastest option is eVetRecs at vetrecs.archives.gov. You verify your identity through ID.me, which may include a live selfie step.⁵ Once you’re verified, you fill out the request online and can check status later using your request number.

By Mail or Fax Using SF-180

If you prefer paper, download Standard Form 180 (“Request Pertaining to Military Records”) from the GSA website. Mail the completed form to the NPRC at 1 Archives Drive, St. Louis, MO 63138, or fax it to 314-801-9195. Federal law requires the request to be signed in cursive and dated within the past year, and you must submit a separate SF-180 for each person whose records you need.⁶

Include as much identifying information as you can: the veteran’s full name used during service, any known Social Security or service number, branch, dates of service, and date and place of birth. The NPRC holds more than 70 million records, so detail speeds the search.

Processing Times and Emergencies

The NPRC receives roughly 4,000 to 5,000 requests per day, and response times vary with workload and the age of the file. The Archives asks that you wait at least 90 days before following up, because duplicate requests slow things down.⁶ For urgent needs such as an upcoming surgery or funeral, flag the request as an emergency through eVetRecs, or note the emergency in the “Purpose” section of the SF-180 and fax it to customer service at 314-801-0764.

Requesting a Deceased Veteran’s Number

Access to a non-public personnel file is limited to the veteran’s next of kin: the unremarried widow or widower, son, daughter, father, mother, brother, or sister.⁷ You’ll need proof of death, such as a death certificate, a letter from the funeral home, or a published obituary.

Files become open to the general public 62 years after the service member separated, on a rolling basis. For requests made in 2026, records of anyone who left the military before 1964 are archival and available to any requester under the public fee schedule.⁴ Genealogists and historians researching World War II and Korean War veterans usually fall under this rule.

If Your Records Were Lost in the 1973 Fire

A fire at the NPRC on July 12, 1973, destroyed an estimated 16 to 18 million Official Military Personnel Files. There were no duplicates, no microfilm backups, and no indexes for the lost records.⁸ Damage was concentrated in two groups:

Army personnel discharged between November 1, 1912 and January 1, 1960, with roughly 80% of those files destroyed.
Air Force personnel with surnames alphabetically after “Hubbard, James E.” discharged between September 25, 1947 and January 1, 1964, with roughly 75% of those files destroyed.

If your records fall in those ranges, the NPRC will try to reconstruct your file using alternate sources such as VA claims files, Selective Service registration records, pay records, military hospital medical records, state records, and unit files.⁸ Reconstruction takes noticeably longer than a standard request.

Veterans filing a VA disability compensation claim on fire-affected records should complete NA Form 13055 (“Request for Information Needed to Reconstruct Medical Data”) and include as much detail as possible about unit assignments, down to company, battalion, regiment, and squadron. The VA encourages working with an accredited attorney, claims agent, or Veterans Service Organization on these claims because the evidentiary burden is higher when originals are gone.⁹ Buddy statements, accident reports, personal photographs from service, and prescription records can all support the claim.

Fixing an Incorrect Service Number

If your service number, name, dates of service, or other identifying information is wrong in your records, apply for a correction using DD Form 149 (“Application for Correction of Military Records”). Each branch has its own Board for Correction of Military Records, and the service secretary has authority to fix errors or remove injustices.¹⁰

Include everything you have that supports the correction: signed witness statements, documents showing the correct information, and a short written explanation of why the current record is wrong. DD Form 149 is available at VA offices, through veterans organizations, and from the DoD Forms Management Program website. Correction matters most when the error is blocking a benefit or muddying your service history.

1
National Archives. Service Numbers and Social Security Numbers
2
The United States Army. DoD to Drop Social Security Numbers From ID Cards
3
Federal Register. Reduction of Use of Social Security Numbers in the Department of Defense
4
National Archives. Request Military Service Records
5
U.S. Department of Veterans Affairs. Request Your Military Service Records (Including DD214)
6
National Archives. Request Military Personnel Records Using Standard Form 180
7
National Archives. Access to Official Military Personnel Files (OMPF) – Veterans and Next-of-Kin
8
National Archives. The 1973 Fire, National Personnel Records Center
9
U.S. Department of Veterans Affairs. Reconstruct Military Records Destroyed in NPRC Fire
10
National Archives. Correcting Military Service Records