HHS OCR report ยท 2018
San Mateo Medical Center data breach
OCR report facts
- Covered entity
- San Mateo Medical Center
- Entity type
- Healthcare Provider
- State
- California
- Individuals affected
- 5,000
- Submission date
- Nov 13, 2018
- Type of breach
- Unauthorized Access/Disclosure
- Location of breached information
- Other
- Business associate present
- No
- Status
- Archive (closed)
OCR description
On November 13, 2018, OCR received a breach notification report from San Mateo Medical Center (SMMC). SMMC reported that the breach affected approximately 5,000 individuals. After an internal investigation, SMMC determined that the report was filed in error, the incident did not amount to a breach and, the incident should not have been reported since no breach occurred. Based on this information, OCR closed the case.
Text as published on the HHS OCR breach portal.
Frequently asked questions
How many people were affected by the San Mateo Medical Center data breach?
The report to HHS OCR lists 5,000 individuals affected.
When was it reported to HHS?
It was submitted to HHS OCR on Nov 13, 2018.
What type of breach was it?
The OCR portal lists the type of breach as Unauthorized Access/Disclosure, with the breached information located in: Other.
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 San Mateo Medical Center 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 San Mateo Medical Center.