For the 29th time, the OIG has issued a report comparing Medicare Part B drug average sales prices (ASP) and average manufacturer prices (AMP), this report covering all of 2011. The OIG again concludes that the Medicare would realize savings if it exercised its authority to lower reimbursement for Part B drugs when the drugs ASP exceeds its drug’s AMP or widely available market price (WAMP) by a threshold, currently set at 5%. Although CMS has finalized regulations specifying the circumstances under which AMP-based price substitutions could occur, no such substitutions have been made to date. The OIG estimates that if CMS’s price substitution policy had been in effect, Medicare would have saved about $7 million in 2011; this amount would have been doubled if the substitution policy were applied to all codes that exceeded the 5% threshold in one or more quarters of 2011 when complete AMP data were used. CMS concurred with an OIG recommendation to finalize its substitution policy, but it did not support OIG recommendations to expand the substitution policy to include all codes with complete AMP data and certain codes with partial AMP data. CMS also rejected an OIG recommendation to seek a legislative change to require manufacturers of Part B-covered drugs to submit both ASPs and AMPs.