The HHS Office of Inspector General (OIG) has found that Medicare allowed $87 million for medical equipment and supply claims with identical referring physician and supplier national provider identifiers (NPI) between May 23, 2008, and September 30, 2009. This situation was concentrated in certain Healthcare Common Procedure Coding System (HCPCS) codes and geographic locations.   While this practice is permissible until January 3, 2011 under a temporary provision CMS instituted allowing suppliers to use their own NPIs in the referring provider field if they cannot obtain the referring physician’s NPI, the OIG believes that “vulnerability remains.” The OIG believes CMS should end this temporary provision as soon as possible.