Enrollment screenings for Medicare beneficiaries are weak, and the Centers for Medicare & Medicaid Services needs to improve verifying provider practice locations and physician licensure statuses, according to a new federal report.

The Government Accountability Office examined the implementation of four CMS enrollment screening procedures, used to detect potentially fraudulent providers and suppliers. Medicare providers are required to submit addresses of their practice locations, but the found 22% of the addresses are “potentially ineligible,” according to the GAO’s June report. Additionally, in March 2014, the CMS reduced the amount of independent verification conducted by contractors, making the program more vulnerable to potential fraud, the report asserted.

CMS contractors must verify physician’s licenses and any self-reported adverse actions while in the Medicare program. The March 2014 report, however, did not include adverse-action history after enrollment. As a result, physicians with any criminal record were not revoked from the Medicare program for months, or ever.

Two other examined procedures appeared to be successful at preventing excluded suppliers and providers from participation in healthcare-related programs, the GAO said.