Every public data breach

44 disclosed this week · 26,355 on record

Medical College of Wisconsin

Disclosed Nov 14, 2023240,667 affectedConfirmed

Official notice

The covered entity (CE), Medical College of Wisconsin, reported that its third-party vendor experienced a cybersecurity incident that allowed unauthorized access to its server and compromised the protected health information (PHI) of 240,667 individuals. The PHI involved included names, addresses, Social Security numbers, dates of birth, claims information, diagnoses, lab results, and medications. The CE notified HHS, affected individuals, and the media. In its mitigation efforts, the CE provided credit monitoring services and terminated its business relationship with the vendor.

What is known

People affected240,667 (as reported to HHS)
DisclosedNov 14, 2023
AttackHacking
Data exposedNamesHealth
SectorHealthcare · US
StatusConfirmed

Sources

Notices filed

Other breaches at Medical College of Wisconsin

History of this record
Added2026-09-25
First recordedby backfillSource

First seen 2026-09-25 (HHS archive), confirmed by HHS OCR. Record counts are as reported. Not legal advice.

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