US Office of Personnel Management

Disclosed Jun 4, 20154,200,000 affectedConfirmed

OPM personnel records of 4.2 million federal employees stolen

OPM discovered that personnel data of 4.2 million current and former federal employees, including names, birth dates, home addresses and Social Security numbers, had been stolen.

What is known

People affected	4,200,000 (as reported by the organization)
Disclosed	Jun 4, 2015
Attack	Hacking
Data exposed	NamesDates of birthAddressesSocial Security numbersEmployment
Sector	Government · US
Status	Confirmed

Sources

Official noticeweb.archive.org

OPM: Cybersecurity Incidents

Notices filed

TotalJun 4, 2015

Research4,200,000 people

Other breaches at US Office of Personnel Management

Background investigation files of 21.5 million people stolen from OPMHacking exposed names, Social Security numbers, biometric data, credentials and tokens, employment records, addresses and dates of birth.Hacking22M affectedGovernmentUSJul 9, 2015

History of this record

Added2026-09-25

First recordedby seedSource

First seen 2026-09-25 (Research), confirmed by Research. Record counts are as reported. Not legal advice.

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