Yale New Haven Health Data Breach Impacts Millions

Yale New Haven Health has experienced a significant cybersecurity breach affecting over 5.5 million individuals, making it one of the largest healthcare data breaches of 2025. The breach, detected on March 8, involved unauthorized access to parts of the network, with patient information such as names, dates of birth, addresses, contact details, race or ethnicity, Social Security numbers, patient type, and/or medical record numbers potentially compromised, though not all data points were accessed for every patient. No electronic medical record system, financial accounts, or employee HR data were compromised. The health system has begun notifying affected individuals and is offering credit monitoring and identity protection to those whose Social Security numbers were involved. At least two federal lawsuits have been filed by patients alleging harm from the breach. This incident highlights growing cybersecurity risks in the healthcare sector.