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U.S. Department of Defense (Defense Manpower Data Center) data breach

Was I affected?

U.S. Department of Defense (Defense Manpower Data Center) confirmed a breach affecting about 3.1 million people, exposing Social Security numbers, names, dates of birth and phone numbers. You may be affected if you are (or were) a U.S. service member, Defense Department civilian employee, contractor or military family member and received a DMDC breach letter in or after September 2026.

U.S. Department of Defense (Defense Manpower Data Center) breach facts
AnnouncedSep 24, 2026
When it happenedOctober 2025 – July 16, 2026
CountryUnited States
People affected3.1 million
Data exposedSocial Security numbers, Names, Dates of birth, Phone numbers, Email addresses, Addresses and Other details
StatusConfirmed by the company or a regulator filing

What happened

The Pentagon's Defense Manpower Data Center (DMDC), which holds personnel records for troops, civilian employees, contractors, retirees, veterans and military families, said a small number of unauthorized users accessed unencrypted files through a security flaw in a file-sharing system between October 2025 and July 16, 2026, when the flaw was found and patched. A Defense Department official said the breach affects 2.76 million living people and 294,000 deceased people. Each person's Social Security number was exposed along with at least one other item such as name, date of birth, contact information, sex, race or military job information. DMDC began mailing letters around September 18, says it has no sign the data has been misused, and is offering 12 months of credit monitoring through IDX.

What should I do?

  1. Enroll in the free 12-month IDX credit monitoring described in your DMDC letter (the enrollment deadline reported is August 19, 2027).
  2. Place a credit freeze with Equifax, Experian and TransUnion, since your Social Security number was exposed.
  3. Get an IRS Identity Protection PIN to block tax-return fraud using your SSN.
  4. Treat unexpected calls, texts or social media messages about your military service or job with caution; this data can be used for targeted phishing.
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