Corewell Health reported that a former consulting vendor, Pinnacle Holdings, LTD, experienced a security incident with unauthorized activity in November 2024, affecting roughly 19,000 Corewell patients. Disclosures described broad possible data categories typical of healthcare vendor breaches; individuals should rely on official notification letters for their specific exposure.
Canonical record: Corewell Health 2026 on BreachHistory.
Sources: The Detroit News, FOX 2 Detroit