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Sierra Management Group

Disclosed Jun 7, 20263 months ago1,279 affectedConfirmed

Official notice

What is known

People affected1,279 (as reported to HHS)
DisclosedJun 7, 2026
AttackHacking
Data exposedNames, Health
SectorHealthcare · US
StatusConfirmed

Sources

Source
California Attorney General breach notice: Sierra Management Groupoag.ca.gov · Official notice
HHS OCR breach report: Sierra Management Group (Business Associate, CA)ocrportal.hhs.gov · Official notice

Notices filed

WhereFiledPeople
HHS OCRtotalJun 71,279
California AGresidents of CAJun 29
History of this record
  • 2026-09-25 · sector: other to health · backfill source
  • 2026-09-25 · attack: unknown to hacking · backfill source
  • 2026-09-25 · data_types: [] to ["names","health"] · backfill source
  • 2026-09-25 · records_basis: empty to hhs · backfill source
  • 2026-09-25 · records: empty to 1279 · backfill source
  • 2026-09-25 · disclosed: 2026-06-29 to 2026-06-07 · backfill source
  • 2026-09-25 · added · backfill source

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

Everything about Sierra Management Group

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