Petaluma Health Center

Disclosed Apr 24, 2023124,862 affectedConfirmed

The covered entity (CE), Petaluma Health Center, reported that it experienced a ransomware attack that compromised the protected health information (PHI) of 124,862 individuals. The PHI involved included names, dates of birth, addresses, Social Security numbers, and treatment and health insurance information. The CE notified HHS, affected individuals, the media, and posted substitute notice to its website. In its mitigation efforts, the CE implemented additional administrative and technical safeguards to better protect its PHI. OCR provided technical assistance regarding the HIPAA Rules.

What is known

People affected	124,862 (as reported to HHS)
Disclosed	Apr 24, 2023
Discovered	Mar 14, 2023
Happened	Mar 7, 2023
Attack	Hacking
Data exposed	NamesHealth
Sector	Healthcare · US
Status	Confirmed

Sources

Official noticeoag.ca.gov

California Attorney General breach notice: Petaluma Health Center

Official noticejustice.oregon.gov

Oregon DOJ breach notice: Petaluma Health Center

Official noticein.gov

Indiana Attorney General 2023 data breach report: Petaluma Health Center

Official noticeocrportal.hhs.gov

HHS OCR breach report (archive, resolved): Petaluma Health Center (Healthcare Provider, CA)

Notices filed

Residents of INApr 24, 2023

Indiana AG2 people

Residents of CAApr 28, 2023

California AGCount not stated

Residents of CAJun 2, 2023

California AGCount not stated

Residents of ORJun 2, 2023

Oregon DOJ482 people

TotalJun 2, 2023

HHS archive124,862 people

Other breaches at Petaluma Health Center

Breach, details not statedBreach notice filed with the California AG, details not stated.HealthcareUSJan 20

History of this record

attack2026-09-25

unknown to hackingby backfillSource

data_types2026-09-25

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

records_basis2026-09-25

organization to hhsby backfillSource

records2026-09-25

2 to 124862by backfillSource

summary2026-09-25

empty to The covered entity (CE), Petaluma Health Center, reported that it experienced a ransomware attack that compromised the protected health information (PHI) of 124,862 individuals. The PHI involved included names, dates of birth, addresses, Soby backfillSource

records_basis2026-09-25

empty to organizationby backfillSource

records2026-09-25

empty to 2by backfillSource

disclosed2026-09-25

2023-04-28 to 2023-04-24by backfillSource

discovered2026-09-25

empty to 2023-03-14by backfillSource

disclosed2026-09-25

2023-06-02 to 2023-04-28by backfillSource

Added2026-09-25

First recordedby backfillSource

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

Everything about Petaluma Health Center