Quantum Health, Inc. notified Massachusetts residents of a data breach involving unauthorized access to its IT network. The incident was triggered by a vishing call on May 29, 2026, leading to the exfiltration of personal and health information, including SSNs and insurance details. The breach was discovered on June 1, 2026, and notifications were sent on July 8, 2026. Quantum Health engaged forensic experts and is offering complimentary identity monitoring services.