HHS OCR report · 2023
Prospect Medical Holdings, Inc. data breach
OCR report facts
- Covered entity
- Prospect Medical Holdings, Inc.
- Entity type
- Business Associate
- State
- California
- Individuals affected
- 1,309,096
- Submission date
- Sep 29, 2023
- Type of breach
- Hacking/IT Incident
- Location of breached information
- Network Server
- Business associate present
- Yes
- Status
- Archive (closed)
OCR description
The covered entity (CE), Prospect Medical Holdings, reported that it experienced a ransomware incident that affected the protected health information (PHI) of 1,309,096 individuals. The PHI involved included names, dates of birth, drivers’ license and Social Security numbers, addresses, diagnoses, lab results, medications, claims and financial information, and other treatment information. The CE notified HHS, affected individuals, the media, and posted substitute notice on its website. In res...
Text as published on the HHS OCR breach portal.
Frequently asked questions
How many people were affected by the Prospect Medical Holdings, Inc. data breach?
The report to HHS OCR lists 1,309,096 individuals affected.
When was it reported to HHS?
It was submitted to HHS OCR on Sep 29, 2023.
What type of breach was it?
The OCR portal lists the type of breach as Hacking/IT Incident, with the breached information located in: Network Server.
Is the investigation still open?
No. The report is in the OCR portal archive, which holds reports where OCR has closed its review.
Is a breach notice letter from Prospect Medical Holdings, Inc. legitimate?
This site cannot verify letters. Check the sender against the organisation's official website and the HHS OCR breach portal, and avoid calling numbers or clicking links only listed in an unexpected message. See our guide on what to do after a data breach notice.
Source: HHS OCR Breach Portal, OCR export October 2026. Network USA is not affiliated with HHS or Prospect Medical Holdings, Inc..