MedStar Health medstarhealth.org MedStar Health data breach: what happened and what to do
MedStar Health said someone accessed its systems from September 12 to 16, 2025. Files held names, birth dates and Social Security numbers, and for some patients diagnoses, medications and insurance details. Notices began December 3, 2025.
View all 13,115 breaches- Breach date
- 12 Sept 2025
- Data exposed
- Names, Dates of birth, Social security numbers, Diagnoses, Medications, Health insurance information, Treatment information
- Last updated
What happened
MedStar Health, which runs 10 hospitals in the Baltimore-Washington area, disclosed a cyberattack it identified on October 4, 2025. Its notice says an unauthorized party had access between September 12 and 16, 2025.
The files involved included patient names, dates of birth and Social Security numbers. For some people they also held information related to care: diagnoses, medications, test results, images, health insurance and treatment details. MedStar began mailing notification letters on December 3, 2025.
MedStar is offering free identity monitoring to patients whose Social Security or driver's license numbers may have been involved. A call center is listed on the notice at medstarhealth.org/data-incident. Reports say MedStar hasn't published how many patients were affected. A ransomware group made its own claims about the size of the data, but that is the attacker's statement, not a confirmed figure.
Medical details combined with an SSN give criminals what they need for medical identity theft and convincing phishing, for example a message that mentions a real diagnosis or provider. Health data can't be changed like a password, so the practical steps are about watching for misuse.
What to do if you were in it
- 1
Freeze your credit
Place a free freeze with Equifax, Experian and TransUnion so no one can open credit with your SSN.
- 2
Take the identity monitoring
If your letter offers it, enroll before the deadline in the notice.
- 3
Check your medical and insurance records
Read explanation-of-benefits statements and ask your insurer about services you don't recognize.
- 4
Expect health-themed phishing
Treat calls, texts and emails about your care or bills as suspect. Call the provider on a number you look up yourself.
- 5
Check whether your email or phone is in this and other breaches
Run a free Serus scan. It checks breach databases and the dark web for your email and phone number and tells you what to do next.
Frequently asked
Was I affected by the MedStar Health data breach?
MedStar mailed notices starting December 3, 2025. Call the center on its data incident page if you think you should have one.
What was exposed?
Names, dates of birth and Social Security numbers, and for some patients diagnoses, medications, test results, insurance and treatment information.
Is there a lawsuit?
Coverage reports consolidated proposed federal class action litigation over the incident. Check the court docket or the MedStar notice for any settlement terms.
Sources
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