APOLLOMD disclosed a data breach that exposed the personal information of more than 626,000 individuals linked to affiliated physicians and practices, following a cyberattack in May 2025. The exposed data varied by person and included names, dates of birth, addresses, diagnoses, treatment details, insurance data and, in some cases, Social Security numbers.
The company detected unusual activity on 22 May 2025, launched an investigation with a forensic firm, and notified law enforcement; investigators found that an unauthorized party accessed ApolloMD’s IT systems between 22 and 23 May 2025, potentially accessing and acquiring patient files. Notification letters began being mailed to affected patients on 17 September 2025, with practices informed between July and September 2025.
According to the US Department of Health and Human Services, the exact number of impacted people is 626,540. The Qilin ransomware group claimed the data breach in June 2025, although ApolloMD did not publish technical details of the incident.