- State
- CA
- Covered entity type
- Health Plan
- Individuals affected
- 11,894
- Business associate present
- No
- Type of breach
- Hacking/IT Incident
- Location of breached information
- First seen by InfoSec Signals
- 9/23/2026
- Last seen in OCR export
- 9/23/2026
OCR description
The covered entity (CE), Health Plan of San Mateo, reported that an employee was the subject of an email phishing scheme that affected the protected health information (PHI) of 11,894 individuals. The PHI involved included names, dates of birth, diagnoses/conditions, medications, and other treatment information. The CE notified HHS, affected individuals, the media, and posted substitute notice on its website. In response to the breach, the CE implemented additional administrative, technical, and security safeguards.
Change history
- 9/23/2026Added to OCR's archive list
Source: U.S. Department of Health and Human Services, Office for Civil Rights, Breach Portal. Records are reproduced as published; entity names and figures are OCR's.