Marietta, Ga.-based Pinnacle Orthopaedics & Sports Medicine Specialists suffered a data breach, the practice said June 21.
Around April 22, the practice noticed suspicious activity in its network and launched an investigation, according to a news release. The investigation found that an unknown person gained access to a limited portion of the practice's network.
Initially the practice identified fewer than 10 affected patients. However in June the practice determined that more than 500 patients may have been affected.
The investigation is ongoing, and notifications are being sent out to patients.