A recent GAO report examines the growing prevalence of physician self-referral (referral to the physician’s own practice) for advanced imaging services (e.g., magnetic resonance imaging (MRI) and computed tomography (CT) services) and its effect on Medicare spending. The GAO reports that while the number of both self-referred and non-self-referred advanced imaging services increased from 2004 through 2010, the growth rate was much higher for self-referred services. For instance, the number of self-referred MRI services increased by more than 80% during this period, compared to a 12% growth rate for non-self-referred MRI services. Self-referring providers referred about twice as many MRI and CT services as providers who did not self-refer in 2010, and these differences persisted even after accounting for practice size, specialty, geography, or patient characteristics. The GAO also found that providers' referrals of MRI and CT services substantially increased the year after they purchased or leased imaging equipment or joined a group practice that self-referred. The GAO estimates that providers who self-referred likely made 400,000 more referrals for advanced imaging services in 2010 than they would have if they were not self-referring, increasing Medicare costs by about $109 million. The GAO points out that any unnecessary referrals “pose unacceptable risks for beneficiaries, particularly in the case of CT services, which involve the use of ionizing radiation that has been linked to an increased risk of developing cancer.” The GAO recommends that CMS take steps to improve its ability to identify self-referral of advanced imaging services and address increases in these services, including: inserting a self-referral flag on Medicare Part B claims form to indicate whether or not an advanced imaging service is self-referred; implementing a payment reduction for self-referred advanced imaging services to “recognize efficiencies when the same provider refers and performs a service”; and determining how to ensure the appropriateness of advanced imaging services referred by self-referring providers.