McLaren Health Care

Disclosed Jun 20, 2025743,131 affectedConfirmed

INC ransomware attack on McLaren exposed data of 743,131 patients

McLaren Health Care began notifying 743,000 patients that a July 2024 INC ransomware attack, discovered August 5, 2024, exposed their data; the investigation finished May 5, 2025.

What is known

People affected	743,131 (as reported to HHS)
Disclosed	Jun 20, 2025
Discovered	Aug 5, 2024
Happened	Jul 17, 2024
Attack	Ransomware
Data exposed	NamesHealthSocial Security numbersInsuranceDates of birthOther
Sector	Healthcare · US
Status	Confirmed

Sources

Official noticeocrportal.hhs.gov

HHS OCR breach report: McLaren Health Care (Healthcare Provider, MI)

Newsbleepingcomputer.com

McLaren Health Care says data breach impacts 743,000 patients

Newshipaajournal.com

June 2025 Healthcare Data Breach Report

Official noticeago.vermont.gov

Vermont Attorney General: 2025-06-20 McLaren Health Care Data Breach Notice to Consumers

Official noticein.gov

Indiana Attorney General 2025 data breach report: McLaren Health Care

Notices filed

TotalJun 20, 2025

Research743,131 people

Residents of VTJun 20, 2025

Vermont AGCount not stated

Residents of INJun 20, 2025

Indiana AG530 people

TotalJun 24, 2025

HHS OCR743,131 people

Other breaches at McLaren Health Care

Hacking breachHacking exposed names and health records. Reported to the California AG.2.1M affectedHealthcareUSOct 20, 2023 Hacking breachHacking exposed names and health records. Reported to the HHS archive.65K affectedHealthcareUSJul 16, 2021

History of this record

occurred2026-09-25

empty to 2024-07-17by backfillSource

source2026-09-25

empty to https://ago.vermont.gov/document/2025-06-20-mclaren-health-care-data-breach-notice-consumersby backfillSource

attack2026-09-25

hacking to ransomwareby seedSource

data_types2026-09-25

["names","health"] to ["names","health","ssn","insurance","dob","other"]by seedSource

disclosed2026-09-25

2025-06-24 to 2025-06-20by seedSource

discovered2026-09-25

empty to 2024-08-05by seedSource

summary2026-09-25

empty to McLaren Health Care began notifying 743,000 patients that a July 2024 INC ransomware attack, discovered August 5, 2024, exposed their data; the investigation finished May 5, 2025.by seedSource

title2026-09-25

empty to INC ransomware attack on McLaren exposed data of 743,131 patientsby seedSource

Added2026-09-25

First recordedby backfillSource

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

Everything about McLaren Health Care