Yale New Haven Health data breach affects 5.5 million patients

Yale New Haven Health confirmed a cyber incident that resulted in a data breach impacting 5,556,702 patients; exposed data may include names, dates of birth, addresses, phone numbers, email addresses, race/ethnicity, medical record numbers, patient type, and Social Security numbers. The system disruption occurred in March 2025, Mandiant was retained to assist with restoration and investigation, federal authorities were notified, affected patients have been offered credit monitoring, and class-action lawsuits are being prepared while the attackers remain unidentified.