One Medical Seniors (a subsidiary of 1Life Healthcare) notified Massachusetts residents of a security event involving a third-party file-storage system used for archived One Medical Seniors (formerly Iora Health) patient data. Between June 8-11, 2026, an unauthorized person accessed patient files containing PHI (treatment plans, diagnostics, prescriptions) and PII (contact info, SSN/Medicare numbers). The incident was contained on June 13, 2026, by revoking access and rotating credentials. Affected individuals were offered 24 months of Experian IdentityWorks.