Narrative review: The U.S. Pharmacopeia and Model Guidelines for medicare Part D formularies

The Medicare Prescription Drug, Improvement, and Modernization Act of 2003 includes a provision directing the Secretary of the U.S. Department of Health and Human Services to request that the U.S. Pharmacopeia (USP) develop a list of categories and classes (the USP Model Guidelines) that can be used by prescription drug plans in developing their formularies for the Part D prescription drug benefit. The Centers for Medicare & Medicaid Services (CMS) used the Model Guidelines and USP's related listing, termed the Formulary Key Drug Types, to evaluate prescription drug plan formularies submitted by prescription drug plan sponsors intending to provide the new Part D benefit. This article recounts how USP's all-volunteer Model Guidelines Expert Committee developed the USP Model Guidelines and Formulary Key Drug Types, working under a cooperative agreement with CMS in response to the Secretary's request. The Model Guidelines and Formulary Key Drug Types are updated annually to reflect advances in evidence-based medicine, thereby offering timely guidance to CMS and to prescription drug plans based on USP's demonstrated expertise in setting standards.