As of January 1, 2026, all Medicare Part D plans are required to cover ten prescription drugs selected for price negotiation under the Inflation Reduction Act (IRA), a change that has already led to improved access to several key medications, according to a recent analysis.
The analysis, which examined 2026 formulary coverage, reveals that coverage rates have increased for nine of the first ten drugs subject to negotiation compared to 2025, before the IRA’s coverage requirement took effect. The IRA, signed into law in 2022, aims to lower prescription drug costs for Medicare beneficiaries and reduce federal spending. A key component of the law is the Medicare Drug Price Negotiation Program, which allows the government to negotiate the prices of some high-cost drugs covered by Medicare.
Significant gains in coverage were observed for specific dosages and forms of insulin products like Fiasp and NovoLog. In 2025, Fiasp was covered by plans enrolling 24% of Part D enrollees, while NovoLog was covered for 32%. Coverage also expanded for two dosages of Imbruvica, a cancer drug, which was available to roughly half of Part D enrollees in 2025.
The IRA’s impact extends beyond the initial ten drugs. Fifteen additional drugs were selected for negotiation, with negotiated prices slated to take effect in 2027. Among these is Wegovy, a GLP-1 drug used for obesity and cardiovascular disease risk reduction. Currently, Wegovy is covered by fewer than 1% of Part D plans, but Medicare’s prohibition on covering drugs solely for weight loss limits its accessibility. Still, a temporary, voluntary model is planned by the Trump administration to expand Medicare coverage of GLP-1s for obesity treatment beginning in 2027, potentially increasing access for beneficiaries in participating plans.
The IRA’s coverage requirement is expected to further broaden access to several other drugs with negotiated prices available in 2027. These include Austedo and Austedo XR, treatments for involuntary movement disorders; Otezla, for psoriasis and psoriatic arthritis; and Breo Ellipta, for asthma and COPD. As of 2026, Austedo is covered for 72% of enrollees, Austedo XR for 51%, Otezla for 68%, and Breo Ellipta for 74%.
Notably, six of the fifteen drugs selected for negotiation in 2027 already benefit from broad coverage due to their inclusion in protected classes of drugs that all Part D plans are required to cover. These include antineoplastics like Xtandi, Pomalyst, Ofev, Ibrance, and Calquence, as well as the antipsychotic Vraylar.
The Centers for Medicare & Medicaid Services (CMS) initially announced the first 10 drugs selected for negotiation in September 2023, with the negotiated prices becoming effective on January 1, 2026. The second set of 15 drugs was announced in March 2024, with their negotiated prices scheduled to take effect in 2027.