CMS Notifies Individuals Potentially Impacted by Data Breach | CMS. The Centers for Medicare & Medicaid Services (CMS) and Wisconsin Physicians Service Insurance Corporation (WPS) are notifying people whose protected health information or other personally identifiable information (PII) may have been compromised in connection with Medicare administrative services provided by WPS. WPS is a CMS contractor that handles Medicare Part A/B claims and related services for CMS. Third-party company: Wisconsin Physicians Service Insurance Corporation (WPS).