The OIG has begun to analyze the extent to which and reasons why physicians opt out of the Medicare program, along with the effects on Medicare beneficiaries. The OIG was not able to complete its assessment because no centralized data exist. Limited data reviewed by the OIG indicate that the number of opted-out physicians appears to have increased each year from 2006 to 2010, and the OIG suggests that “[m]ore physicians may opt out in the near future, given the potential for legislated decreases in Medicare reimbursement for physician services.” The OIG is concerned that data shortcomings and a lack of procedures for Medicare Administrative Contractors’ handling of opted-out physicians impedes CMS’s oversight of this aspect of the Medicare program. The OIG is seeking additional data on physicians who opted out between 1998 and 2008, and will conduct a full evaluation when a complete data source of opted-out physicians is available.