The government is putting millions of Medicare dollars at risk by authorizing fake companies that sell wheelchairs, prosthetics and other medical supplies to submit reimbursement claims, congressional investigators said, according to the Associated Press.

The fictional companies, from Maryland and Virginia, were approved by Medicare to supply medical equipment despite their having no customers and no products in stock after the Government Accountability Office provided false documents and confused information that offered little assurances the companies were legitimate, according to a report by the Government Accountability Office. A GAO investigator even left a “vague message” on the answering machine of the contractor responsible for the investigating the applications, pretending to be a supplier. Roughly $1 billion of the $10 billion in annual Medicare payments the government makes for medical equipment were deemed improper.

“If real fraudsters had been in charge of the fictitious companies, they would have been clear to bill Medicare from the Virginia office for potentially millions of dollars of false supplies,” the GAO said in the report.

The Centers for Medicare and Medicaid Services acknowledged that there were problems with its enrollment procedures. The agency said it recently put in place new standards that require medical suppliers to be certified. According to the AP, among other changes are: requiring that suppliers keep supporting paper work from doctors, limiting use cell phones and pagers as a supplier’s primary business number, setting up a new competitive bidding process for medical equipment. The program will be fully rolled out by September 2009.