In light of a continued high rate of Medicare fee-for-service improper payments (8.6% in FY 2011), the GAO recently assessed the use of Medicare prepayment edits and CMS's oversight of Medicare Administrative Contractors (MACs) that process claims.  In the report, "Medicare Program Integrity: Greater Prepayment Control Efforts Could Increase Savings and Better Ensure Proper Payment," the GAO estimates that while the use of prepayment edits saved Medicare at least $1.76 billion in FY 2010, it believes savings could have been greater if prepayment edits had been more widely used. For instance, the GAO found more than $100 million in Medicare payments that were inconsistent with a sample of three local coverage determinations (pertaining to monitored anesthesia care, parathormone, and noninvasive cerebrovascular studies) and that could have been identified using automated edits. The GAO also found weaknesses associated with CMS edit processes based on national policies, such as lack of specific time frames for implementing edits, flaws in the structure of some edits, and lack of centralized implementation. GAO recommends that CMS take a series of steps to strengthen its use of prepayment edits, such as implementing medically unlikely edits that assess all quantities provided to the same beneficiary by the same provider on the same day; encouraging more information sharing about effective edits, and assessing the feasibility of increasing incentives for edit use. HHS generally agreed with the recommendations.