Assessment of IPAY 2027 Medicare drug price negotiation maximum fair prices with prices in most-favored nation reference countries

BACKGROUND: Prescription drug list prices in the United States far exceed those in peer nations, averaging 278% of non-US prices and 422% for branded products. The Inflation Reduction Act authorized Medicare to negotiate net prices for high-expenditure drugs, resulting in maximum fair prices (MFPs) for 15 Part D products effective in 2027. Subsequently, Centers for Medicare and Medicaid Services (CMS) introduced the GLOBE and GUARD models, which propose a most-favored nation (MFN) pricing framework for both Part B and Part D, respectively, that is tied to international prices in 19 countries. CMS also introduced the GENEROUS model for Medicaid, which uses an 8-country subset of the GLOBE/GUARD reference nations. OBJECTIVE: To evaluate the performance of the Medicare Drug Price Negotiation Program by comparing negotiated net prices with domestic and international list price benchmarks. METHODS: We identified negotiated drugs using CMS publications and estimated initial US net prices and CMS price benchmarks for negotiation including statutory discounts. International list prices from the 19 countries that will be used as reference for the GUARD and GLOBE models were extracted from Eversana's NAVLIN database and converted to US dollars using 2025 exchange rates. Prices were adjusted using purchasing power parity. All prices were standardized to a 30-day equivalent supply following CMS methods. For drugs with multiple brands or strengths, weighted average per-unit prices were estimated using Medicare Part D utilization data. RESULTS: Postnegotiation MFPs were 15% to 60% (median: 38%) lower than estimated US net prices with greater reductions for drugs whose ceiling price was determined by the net price. However, MFPs remained 17% to 755% (median: 108%) higher than the average purchasing power parity-adjusted published list price in MFN reference countries. The mean US-to-international price ratio declined from 5.8 before negotiation to 3.3 afterward. Twelve of 14 drugs had MFPs below their estimated ceilings, whereas the 15th drug had an inestimable ceiling. There is not enough information about the proposed GLOBE and GUARD models to project MFN prices for Part B or D at this time. Discounts varied by therapeutic class and were larger for drugs with prior negotiated comparators. CONCLUSIONS: The 2025 Medicare drug negotiations will generate meaningful reductions in domestic drug prices when they take effect in 2027 but left substantial disparities relative to peer nations. Upcoming MFN-based pricing models may exert further downward pressure, although their implementation and international effects warrant careful monitoring.