Quantum Health

Disclosed Jul 29, 20268 weeks ago625,945 affectedConfirmed

What is known

People affected	625,945 (as reported by the organization)
Disclosed	Jul 29, 2026
Discovered	Jun 1, 2026
Happened	May 29, 2026
Attack	Hacking
Data exposed	Names, Health, Social Security numbers, Insurance
Sector	Healthcare · US
Status	Confirmed

Source	Kind
California Attorney General breach notice: Quantum Healthoag.ca.gov · Official notice	Official notice
Washington Attorney General breach notice: Quantum Healthatg.wa.gov · Official notice	Official notice
Oregon DOJ breach notice: Quantum Healthjustice.oregon.gov · Official notice	Official notice
HHS OCR breach report: Quantum Health (Business Associate, OH)ocrportal.hhs.gov · Official notice	Official notice
Texas Attorney General data security breach report BR-0005262: Quantum Healthoag.my.site.com · Official notice	Official notice

Where	Filed	People
HHS OCRtotal	Jul 29	2,104
California AGresidents of CA	Aug 14
Washington AGresidents of WA	Aug 14	5,909
Oregon DOJresidents of OR	Aug 14	184,376
Texas AGresidents of TX	Aug 18	68,451

Breach	Disclosed	Attack	Sector	Status	Affected
Disclosed Mar 17, 2017Mar 17, 20179 years ago	Mar 17, 20179 years ago	Not stated	Healthcare	Confirmed	737

History of this record

2026-09-25 · data_types: ["names","health"] to ["names","health","ssn","insurance"] · backfill source
2026-09-25 · records_basis: hhs to organization · backfill source
2026-09-25 · records: 2104 to 625945 · 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 2104 · backfill source
2026-09-25 · disclosed: 2026-08-14 to 2026-07-29 · backfill source
2026-09-25 · attack: unknown to hacking · backfill source
2026-09-25 · discovered: empty to 2026-06-01 · 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.