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Congressionally Mandated ASP/AMP Comparisons

When Congress established average sale prices (ASPs) as the primary basis for Medicare Part B drug reimbursement, it also mandated that OIG compare manufacturer-reported ASPs with the average manufacturer prices (AMPs) reported by manufacturers as part of the Medicaid drug rebate program. If OIG finds that the ASP for a drug exceeds the AMP by a certain threshold - currently, 5 percent - CMS is directed to substitute the ASP-based reimbursement amount with the lesser of the widely available market price (if any) or 103 percent of the AMP.

To comply with its statutory mandate, OIG conducts ASP/AMP comparisons each quarter and provides our findings to CMS. We also issue an annual public report summarizing the results of these quarterly comparisons (Note: OIG also published the quarterly comparisons as individual reports through 2012.) In April 2013, CMS began substituting reimbursement amounts in accordance with its published price substitution policy, which currently applies to only certain drug codes with complete AMP data that exceed the 5-percent threshold in two consecutive quarters or three of the previous four quarters.

Annual Reports

Report Title Issue Date
Medicare Part B Drug Payments: Impact of Price Substitutions Based on 2016 Average Sales Prices (OEI-03-18-00120) August 2018
Medicare Part B Drug Payments: Impact of Price Substitutions Based on 2015 Average Sales Prices (OEI-03-17-00360) September 2017
Medicare Part B Drug Payments: Impact of Price Substitutions Based on 2014 Average Sales Prices (OEI 03-16-00540 August 2017
Comparing Average Sales Prices and Average Manufacturer Prices for Medicare Part B Drugs: An Overview of 2013 (OEI-03-14-00520) 2/1/2015
Comparing Average Sales Prices and Average Manufacturer Prices for Medicare Part B Drugs: An Overview of 2012 (OEI-03-13-00570) 3/1/2014
Comparison of Average Sales Prices and Average Manufacturer Prices: An Overview of 2011 (OEI-03-12-00670) 2/1/2013
Comparison of Average Sales Prices and Average Manufacturer Prices: An Overview of 2010 (OEI-03-11-00410) Nov-11
Comparison of Average Sales Prices and Average Manufacturer Prices: An Overview of 2009 (OEI-03-11-00380) Apr-11
Comparison of Average Sales Prices and Average Manufacturer Prices: An Overview of 2008 (OEI-03-09-00350) Feb-10
Comparison of Average Sales Prices and Average Manufacturer Prices: An Overview of 2007 (OEI-03-08-00450) Dec-08
Monitoring Medicare Part B Drug Prices: A Comparison of Average Sales Prices to Average Manufacturer Prices (OEI-03-04-00430) Apr-06

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