A recent Government Accountability Office (GAO) report, “Medicare Part B: CMS Should Take Additional Steps to Verify Accuracy of Data Used to Set Payment Rates for Drugs,” questions the reliability of pricing for Medicare Part B drugs reimbursed based on average sales price (ASP). The GAO observes that while CMS performs various electronic checks of manufacturer-submitted data (e.g., checking for missing data or incorrect product information), CMS does not routinely verify the underlying data. Furthermore, because the Social Security Act only requires manufacturers with Medicaid drug rebate agreements to submit ASP data to CMS, in some cases CMS cannot set payment based on ASP unless manufacturers without rebate agreements choose to voluntarily submit sales price data. The GAO recommends that Congress consider requiring all manufacturers of drugs paid at ASP to submit sales price data to CMS. The GAO also calls on CMS to periodically verify the data submitted by a sample of drug manufacturers by requesting source documentation. In comments on the report, HHS agreed, stating that CMS will work with the OIG as appropriate to collect source document from drug manufacturers and will take action as warranted.