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.
2026-09-25 · disclosed: 2023-03-17 to 2023-01-18 · 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 11894 · backfill source
2026-09-25 · summary: empty to 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 b · backfill source
