HHS OCR report ยท 2018
MSK Group data breach
OCR report facts
- Covered entity
- MSK Group
- Entity type
- Healthcare Provider
- State
- Tennessee
- Individuals affected
- 566,236
- Submission date
- May 22, 2018
- Type of breach
- Hacking/IT Incident
- Location of breached information
- Network Server
- Business associate present
- No
- Status
- Archive (closed)
OCR description
The covered entity (CE), MSK Group PC, discovered on May 7, 2018, that ransomware blocked access to its computer servers which the contained electronic protected health information (ePHI) of 566,236 former and current patients. The ePHI potentially affected included demographic, clinical, and health insurance information. The CE was unable to determine whether ePHI had been copied or transferred outside of the network. The CE timely performed its breach notification obligations. In respon...
Text as published on the HHS OCR breach portal.
Frequently asked questions
How many people were affected by the MSK Group data breach?
The report to HHS OCR lists 566,236 individuals affected.
When was it reported to HHS?
It was submitted to HHS OCR on May 22, 2018.
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 MSK Group 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 MSK Group.