Massachusetts General Hospital

Disclosed Jun 29, 20164,293 affectedConfirmed

Hackers caused a breach of protected health information (PHI) at Patterson Dental Supply, Inc., a business associate (BA) of the covered entity (CE), Massachusetts General Hospital. The breach affected the PHI of approximately 4,293 individuals, and included demographic and clinical information. The CE provided breach notification to HHS, affected individuals, and the media. OCR’s investigation revealed that the CE and BA had a business associate agreement in place at the time of the breach. OCR reviewed the BA agreement and determined that it appeared to comply with the requirements of the HIPAA Rules. OCR has opened a separate review of the BA concerning the underlying breach.

What is known

People affected	4,293 (as reported by the organization)
Disclosed	Jun 29, 2016
Attack	Hacking
Data exposed	NamesHealth
Sector	Healthcare · US
Status	Confirmed

Sources

Official noticein.gov

Indiana Attorney General 2016 data breach report: Massachusetts General Hospital

Official noticeocrportal.hhs.gov

HHS OCR breach report (archive, resolved): Massachusetts General Hospital (Healthcare Provider, MA)

Notices filed

Residents of INJun 29, 2016

Indiana AG3 people

TotalJun 29, 2016

HHS archive4,293 people

Other breaches at Massachusetts General Hospital

Breach, details not statedBreach notice filed with the Vermont AG, details not stated.HealthcareUSFeb 21, 2024 Hacking breachHacking exposed names and health records. Reported to the HHS archive.9,900 affectedHealthcareUSDec 14, 2018 Breach, details not statedExposed names, Social Security numbers and names. Reported to the Maine AG.HealthcareUSMar 21, 2017 Insider breachInsider exposed names and health records. Reported to the HHS archive.648 affectedHealthcareUSAug 5, 2014

History of this record

attack2026-09-25

unknown to hackingby backfillSource

data_types2026-09-25

[] to ["names","health"]by backfillSource

summary2026-09-25

empty to Hackers caused a breach of protected health information (PHI) at Patterson Dental Supply, Inc., a business associate (BA) of the covered entity (CE), Massachusetts General Hospital. The breach affected the PHI of approximately 4,293 individby backfillSource

Added2026-09-25

First recordedby backfillSource

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

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