The OIG has issued a report identifying a number of potential vulnerabilities associated with Medicare payment for Part B services billed by physicians but performed by nonphysicians under the "incident to" rule. In particular, the OIG raised concerns regarding the performance of invasive services by unqualified nonphysicians. The OIG recommends revisions to the "incident to" rule, including new limits on the circumstances under which physicians who do not personally perform the services may bill Medicare.