Beginning September 1st, CMS will be utilizing FDA’s online NDC Structured Product Labeling Data Elements (NSDE) file to edit Part D prescription drug event data (PDEs). Currently, CMS uses First Databank and MediSpan to edit NDCs on PDEs. Starting in September, CMS will no longer accept NDCs that have not been electronically listed (e-listed) with the FDA. CMS is implementing this requirement to help ensure that the Medicare Part D program only pays for Part D drugs that are currently and legally on the market. In turn, Part D sponsors will likely begin rejecting pharmacy claims submitted that include NDCs that have not been e-listed with the FDA. While a small percentage of Part D claims currently involve unlisted NDCs, some pharmacies could be affected more than others depending upon which NDCs they currently stock and/or submit claims for. Pharmacy systems that permit the selection of outdated or unlisted product codes will be affected the most. NCPA members are encouraged ems vendors and wholesalers to ensure drug products they stock are e-listed with the FDA to minimize any potential disruption.