Partnership HealthPlan of California

Disclosed Sep 4, 20261,526 affectedConfirmed

Partnership HealthPlan mailings sent other members' health plan data

Partnership HealthPlan of California said some PCP selection forms and welcome packets mailed between May 13 and July 8, 2026 contained names, birth dates and member ID numbers of unrelated members. SSNs and ID numbers were not involved.

What is known

People affected	1,526 (as reported to HHS)
Disclosed	Sep 4, 2026
Discovered	Jul 7, 2026
Happened	May 13, 2026
Attack	Insider
Data exposed	NamesHealthDates of birthInsurance
Sector	Insurance · US
Status	Confirmed

Sources

Official noticeoag.ca.gov

California Attorney General breach notice: Partnership HealthPlan of California

Official noticeocrportal.hhs.gov

HHS OCR breach report: Partnership HealthPlan of California (Health Plan, CA)

Regulatoroag.ca.gov

California AG breach report: Partnership HealthPlan of California

Regulatoroag.ca.gov

Partnership HealthPlan notification letter

Notices filed

TotalSep 4

HHS OCR1,526 people

Residents of CASep 17

California AGCount not stated

TotalSep 17

ResearchCount not stated

Other breaches at Partnership HealthPlan of California

Ransomware breachRansomware exposed names and health records. Reported to the California AG.855K affectedHealthcareUSMay 18, 2022

History of this record

sector2026-09-25

health to insuranceby seedSource

data_types2026-09-25

["names","health"] to ["names","health","dob","insurance"]by seedSource

discovered2026-09-25

empty to 2026-07-07by seedSource

summary2026-09-25

empty to Partnership HealthPlan of California said some PCP selection forms and welcome packets mailed between May 13 and July 8, 2026 contained names, birth dates and member ID numbers of unrelated members. SSNs and ID numbers were not involved.by seedSource

title2026-09-25

empty to Partnership HealthPlan mailings sent other members' health plan databy seedSource

attack2026-09-25

unknown to insiderby backfillSource

data_types2026-09-25

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

records_basis2026-09-25

empty to hhsby backfillSource

records2026-09-25

empty to 1526by backfillSource

disclosed2026-09-25

2026-09-17 to 2026-09-04by 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 Partnership HealthPlan of California