Multiple major healthcare data breaches have been officially logged on the US Department of Health and Human Services tracker, with millions of Americans affected. The largest incident impacted New York City Health and Hospitals Corporation, affecting 1.8 million people after hackers accessed systems through a third-party vendor between November 2025 and February 2026, exposing personal, medical, and financial information. Other significant breaches include Erie Family Health Centers in Chicago affecting 570,000 individuals and Florida Physician Specialists impacting 276,000 people, though none of these attacks have been claimed by known cybercrime groups.