Every public data breach

44 disclosed this week · 26,355 on record

Cook County Health and Hospitals System

Disclosed Oct 27, 2017727 affectedConfirmed

Official notice

The covered entity (CE), Cook County Health & Hospitals System (CCHHS), reported that its business associate (BA), Experian Health (Experian), discovered an error in the upgrade of two billing platforms which resulted in the delivery of protected health information (PHI) to the wrong recipients. The PHI involved included names, dates of birth, treatment information, and health insurance information. This breach affected 727 individuals. CCHHS notified HHS, affected individuals, the media, and provided substitute notice. To mitigate this issue, Experian reverted back to its older billing platform to rectify this issue.

What is known

People affected727 (as reported to HHS)
DisclosedOct 27, 2017
AttackInsider
Data exposedNamesHealth
SectorHealthcare · US
StatusConfirmed

Sources

Notices filed

Other breaches at Cook County Health and Hospitals System

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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