Sanford Health, which uses the vendor for its mobile heart screen trucks, said patient names, dates of birth, dates of service, physician name and exam type might have been compromised due to the breach on DMS.
According to the publication, more than 21,000 patients from Sanford are being notified of the data breach.
Those affected will receive free credit monitoring from DMS.
Sioux Fall-based Avera Health was also affected by the breach on DMS.