Marin Cancer Care
Disclosed Feb 6, 20267 months ago27,332 affectedConfirmed
The covered entity (CE), Marin Cancer Care, reported that it experienced a cybersecurity incident that affected the protected health information (PHI) of 27,332 individuals. The PHI involved included demographic, clinical, and financial information. The CE notified HHS, affected individuals, and provided media notice. In response to the breach, the CE implemented additional administrative and technical safeguards.
What is known
| People affected | 27,332 (as reported to HHS) |
|---|---|
| Disclosed | Feb 6, 2026 |
| Happened | Nov 22, 2025 |
| Attack | Hacking |
| Data exposed | Names, Health |
| Sector | Healthcare · US |
| Status | Confirmed |
Sources
| Source | |
|---|---|
| California Attorney General breach notice: Marin Cancer Careoag.ca.gov · Official notice | Official notice |
| Vermont Attorney General breach report: Marin Cancer Careago.vermont.gov · Official notice | Official notice |
| HHS OCR breach report (archive, resolved): Marin Cancer Care (Healthcare Provider, CA)ocrportal.hhs.gov · Official notice | Official notice |
Notices filed
| Where | Filed | People |
|---|---|---|
| HHS archivetotal | Feb 6 | 27,332 |
| California AGresidents of CA | Apr 23 | |
| Vermont AGresidents of VT | Apr 23 | 2 |
History of this record
- 2026-09-25 · attack: unknown to hacking · backfill source
- 2026-09-25 · records_basis: empty to hhs · backfill source
- 2026-09-25 · records: empty to 27332 · backfill source
- 2026-09-25 · disclosed: 2026-04-23 to 2026-02-06 · backfill source
- 2026-09-25 · summary: empty to The covered entity (CE), Marin Cancer Care, reported that it experienced a cybersecurity incident that affected the protected health information (PHI) of 27,332 individuals. The PHI involved included demographic, clinical, and financial inf · backfill source
- 2026-09-25 · data_types: [] to ["names","health"] · 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.