The federal program that has kept standalone Medicare drug plan premiums from swinging wildly for the past two years is being retired. The Centers for Medicare & Medicaid Services said in a July 28, 2026 fact sheet that it will discontinue the Part D Premium Stabilization Demonstration at the end of calendar year 2026, returning the standalone prescription drug plan market to ordinary bid-based pricing for 2027. CMS’s own bid data already shows where that pricing lands: a national base beneficiary premium of $41.33 and a national average monthly bid amount of $296.05, the first full year those figures move without the demonstration’s built-in reduction underneath them.
What the Premium Stabilization Demonstration Actually Did
CMS built the demonstration in 2024 as a response to the biggest overhaul of Part D in the program’s history. The Inflation Reduction Act eliminated the coverage gap, capped annual out-of-pocket drug spending, and shifted a much larger share of plan costs onto insurers upfront rather than reimbursing them later through reinsurance. That redesign made it harder for standalone prescription drug plan sponsors to predict their own costs, and CMS worried the resulting bid swings would push beneficiaries out of plans they had counted on. The demonstration was the agency’s fix for that specific transition problem, not a permanent premium subsidy.
The mechanics were concrete. CMS applied a uniform $15 reduction to the base beneficiary premium for every participating standalone plan and capped any plan’s total premium increase at $35 over its 2024 level, with a third element shifting more loss risk onto the government through revised risk corridors. Participation was technically voluntary, but CMS structured the offer so a sponsor who sat out 2025 could never join later, pulling the entire standalone market in at once. With the reduction and cap in place, the 2025 base beneficiary premium landed at $36.78, an increase CMS called modest given the scale of the redesign.
The demonstration was never framed as open-ended. CMS designed it to run for one year plus at least two subsequent demonstration years, with the dollar figures adjusted annually to reflect market conditions, and treated 2025 and 2026 as the stretch when standalone plan sponsors most needed the extra stability. That structure is why the program’s expiration after December 2026 is not a policy reversal so much as the demonstration reaching the finish line CMS built into it from the start.
What the plan letter does not do: An Annual Notice of Change lists what changed, but never compares the plan against the alternatives on cost, drugs and doctors. Run the comparison in The 2027 Medicare Open Enrollment Decision Kit.
Why CMS Is Letting the Cushion Expire
CMS’s own reasoning for the change sits inside the same document that sets the 2027 numbers. The agency said its bid analysis for 2027 indicates that Part D plan sponsors had sufficient experience under the redesigned benefit to support their own bid assumptions, and that it will discontinue the demonstration at the end of CY 2026 to return the program to traditional market conditions in CY 2027. CMS is telling sponsors they no longer need the extra support: two years of real claims experience is enough to price their own risk without a federal reduction underneath every bid.
That does not mean every guardrail disappears. The Inflation Reduction Act’s own statutory cap, separate from the demonstration, still limits how fast the national base beneficiary premium can climb, no more than 6 percent a year between 2024 and 2029. What ends is the additional, voluntary layer CMS stacked on top of that statutory cap: the $15 uniform reduction and the $35 ceiling on any single plan’s total premium increase. Those two protections applied only inside the demonstration years, and neither survives into 2027.
CMS folded the announcement into the same fact sheet that released preliminary 2027 bid information, timed to give plan sponsors the numbers they need to finalize next year’s offerings. The agency said it will publish the full 2027 Medicare Advantage and Part D landscape, including final average premiums, in September, the same schedule it has followed in past years before Open Enrollment opens.
What the 2027 Numbers Mean for a Plan Search
The base beneficiary premium is not what any individual pays; it is the statutory starting point CMS uses to calculate a plan-specific basic premium, built from a formula involving sponsor bids and reinsurance cost estimates. For 2025 and 2026, that starting point had a $15 markdown built in for every participating standalone plan. For 2027, the $41.33 figure is the number on its own, doing the same calculation job it always did but without the demonstration’s subtraction applied first.
The national average monthly bid amount works differently. It is an enrollment-weighted average of what plan sponsors say it will cost to cover an average member, and CMS uses it to size the government subsidy paid to plans. At $296.05 for 2027, that bid amount does not by itself predict any single plan’s premium. What changes is that the $35 ceiling that kept any one plan’s total premium from jumping more than $35 above its 2024 level is gone, so a sponsor bidding aggressively for 2027 has no demonstration-imposed floor stopping a larger increase from reaching its members.
Beneficiaries will see the practical result of the change during Medicare’s Open Enrollment period, which runs October 15 through December 7, when finalized 2027 plan premiums post and any switch to a different standalone drug plan takes effect January 1. Without the demonstration’s cap in the background, a plan that raised its premium sharply for 2027 will not have that increase automatically limited the way a 2025 or 2026 increase would have been.
CMS has not proposed reviving the demonstration for 2028 or beyond, and the fact sheet treats its conclusion as a closed matter rather than a pause. The agency’s own framing, that plan sponsors now have enough experience under the redesigned Part D benefit to bid without the extra protection, is the operative fact for anyone comparing standalone drug plans this fall: the demonstration that shaped 2025 and 2026 premiums is not part of the 2027 calculation.
Comparing Plans Once the Cushion Is Gone
The Annual Notice of Change that standalone drug plan members receive each fall explains what is different about next year’s plan, but it was never built to show how that plan stacks up against the alternatives once the demonstration’s premium cap is gone. A 2027 bid that looks unremarkable on its own can still cost more, cover fewer of a member’s prescriptions, or drop a pharmacy that member has used for years. Sorting that out means checking the new numbers against every other standalone option in the same market, not just reading the one letter the current plan sends.
The 2027 Medicare Open Enrollment Decision Kit is a 42-page decision kit built around a cost calculator spreadsheet that compares plans on cost, drugs and doctors, paired with a prescription-by-plan comparison and a provider call script for confirming the details before switching.
Open the cost calculator spreadsheet inside The 2027 Medicare Open Enrollment Decision Kit.
This article was researched and drafted with the assistance of AI and reviewed by The Money Overview editorial team.
