Every standalone Medicare Part D plan and every Medicare Advantage prescription drug plan must add all fifteen federally negotiated drugs to its formulary starting January 1, 2027, according to the fact sheet the Centers for Medicare & Medicaid Services finalized after the second round of drug price negotiations closed. The mandate covers medicines used for type 2 diabetes, breast cancer, asthma and several other chronic conditions by roughly 5.3 million of the 53 million people enrolled in Part D coverage in 2024. Plans cannot substitute a cheaper alternative or quietly narrow access to avoid paying the government-negotiated price. The requirement follows a year of formal negotiations between CMS and the drugs’ manufacturers that ended November 1, 2025.
Why Every Part D and Medicare Advantage Plan Must Comply
The obligation comes from the same fact sheet CMS finalized once the negotiation period closed. Once CMS and a manufacturer agree on a negotiated price for a selected drug, the formulary requirement is automatic: standalone Part D plans and Medicare Advantage prescription drug plans alike must list that drug, with no discretion to exclude it because of the cost to the plan. That rule applies to all fifteen drugs selected for the program’s second cycle, covering initial price applicability year 2027.
CMS said it will use its comprehensive formulary review process to catch plans that try to blunt the mandate through prior authorization hurdles, step therapy requirements or narrow pharmacy networks rather than outright exclusion. The agency’s fact sheet ties that oversight directly to the same annual review CMS already runs before approving a plan’s drug list for the coming contract year, giving the requirement an existing enforcement mechanism rather than a new one built from scratch.
The formulary mandate is not new to this second cycle. Ten drugs selected under the Inflation Reduction Act’s first round of negotiations already carry the same requirement, with those negotiated prices effective January 1, 2026, and an estimated $1.5 billion in enrollee out-of-pocket savings projected for that year. The fifteen second-cycle drugs add a second wave of mandatory formulary coverage on top of that first list, roughly doubling the number of negotiated drugs a plan cannot omit.
Inside the kit: 51 state Medicare cost-help packs, the new Part D out-of-pocket cap, the prior-authorization appeal steps and a medication and cost tracker. Open The Medicare Cost & Coverage Protection Kit.
The Fifteen Drugs Now Locked Into Every Formulary
The list runs from blockbuster diabetes and weight-loss treatments to niche cancer drugs: Ozempic, Rybelsus and Wegovy; Trelegy Ellipta and Breo Ellipta; Xtandi; Pomalyst; Ofev; Ibrance; Linzess; Calquence; Austedo and Austedo XR; Xifaxan; Vraylar; Tradjenta; Janumet and Janumet XR; and Otezla and Otezla XR. Discounts against 2024 list prices for a 30-day supply range from 38 percent on Austedo to 85 percent on Janumet, according to the negotiated-price infographic CMS released alongside the fact sheet.
Novo Nordisk’s Ozempic, Rybelsus and Wegovy family carries the largest cut in dollar terms, falling to $274 for a 30-day supply from a 2024 list price of $959, a 71 percent reduction on a drug 2.28 million Part D enrollees used in 2024. GlaxoSmithKline’s Trelegy Ellipta drops to $175 from $654, a 73 percent cut, while Merck’s Janumet and Janumet XR fall to $80 from $526. Each price reflects three rounds of negotiation meetings CMS held with the manufacturer between summer and fall 2025 before the negotiation period closed on November 1.
CMS first published this second-cycle list on January 17, 2025, after ranking eligible drugs by total Part D spending and excluding drugs already selected in the program’s first round. The finalized negotiated prices, along with the National Drug Codes each price applies to across different dosage forms and strengths, are posted on the agency’s selected-drugs-and-negotiated-prices page, which plans and pharmacies use to confirm their coverage obligations.
What the Price Cuts Are Worth to Medicare Enrollees
The fifteen drugs accounted for $42.5 billion in total Part D gross covered prescription drug costs in 2024, about 15 percent of all Part D drug spending that year, with enrollees paying $1.7 billion of that out of pocket before any negotiated price applied. Had the negotiated prices been in effect during 2024, CMS estimates Medicare would have saved $12 billion in net covered drug costs, a reduction of about 44 percent compared with actual 2024 spending net of rebates and fees.
Once the prices take hold in 2027, CMS projects that Medicare enrollees using these fifteen drugs will save an estimated $685 million in out-of-pocket costs in that first year, on top of the $2,100 annual cap on Medicare drug costs that already took effect for 2026. The formulary mandate is what turns that projected savings figure into something an enrollee can count on, since a negotiated price does nothing for a beneficiary whose plan simply declines to cover the drug.
CMS has already set the next deadline in motion: the agency published final guidance for a third negotiation cycle on September 30, 2025, covering drugs that would carry negotiated, formulary-mandated prices beginning in 2028, with renegotiation policy and Medicare Part B drug rules expected to follow through 2026. For now, the fifteen drugs named in the fact sheet CMS finalized in November 2025 are the ones every standalone Part D plan and every Medicare Advantage prescription drug plan must carry starting January 1, 2027.
Formulary Coverage Versus Formulary Cost
The formulary mandate settles which fifteen drugs a plan must list starting January 1, 2027, but it does not settle what a specific plan charges once a prescription reaches the pharmacy counter, since tier placement, deductible phase and prior authorization rules still vary by plan and by state. Nothing in the CMS fact sheet tells an enrollee where a drug sits on a particular plan’s cost-sharing tier or what a state’s process looks like when a plan slows access down anyway.
The Medicare Cost & Coverage Protection Kit is a 10-page kit that comes with 51 state Medicare cost-help packs.
Look up the 51 state Medicare cost-help packs in The Medicare Cost & Coverage Protection Kit.
This article was researched and drafted with the assistance of AI and reviewed by The Money Overview editorial team.
