The US is introducing two mandatory pricing models based on International Reference Pricing (IRP) as part of Trump's "most-favored nation" (MFN) strategy. In one model, reimbursement of selected high-cost drugs in Medicare Part B is tied to the lowest adjusted price from a basket of OECD countries, with this approach phased in over seven years.[3] In the first three years, the previous US prices are combined with the MFN price, from the fourth to the seventh year, payments are to be completely based on the MFN price.[3] The second, so-called the GENEROUS (GENErating cost Reductions fOr U.S. Medicaid) model is focused on Medicaid and uses international reference prices to calculate the so-called guaranteed net unit price and additional rebates.[1][2] In the GENEROUS model, MFN prices are determined from the average net prices of producers in a basket of comparable countries (e.g. Canada, France, Germany, Italy, Japan, United Kingdom, Denmark, Switzerland), adjusted according to GDP per capita using the purchasing power parity method.[1] The use of the second lowest price in this basket is intended to limit the impact of extremely low prices while maintaining a link to the international market.[1] Both strategies aim to reduce US drug spending by bringing US prices closer to those in other developed countries.[2][3]