For the past two years, a temporary government backstop has quietly held down what millions of older Americans pay for a standalone Medicare prescription drug plan. The Centers for Medicare & Medicaid Services has confirmed that backstop is ending at the close of this year, meaning standalone drug plan premiums move back to ordinary market pricing starting in January 2027. The change reaches only standalone Part D plans, not the drug coverage bundled inside Medicare Advantage. It arrives just as plan sponsors finish the bids that will set next year’s costs.
The Part D Premium Stabilization Demonstration’s Two-Year Run
CMS calls the program the Part D Premium Stabilization Demonstration, a voluntary arrangement open only to sponsors of standalone prescription drug plans, including employer group waiver plans. The agency built the demonstration to smooth the transition into the redesigned Part D benefit created by the Inflation Reduction Act, which restructured how drug costs are shared among beneficiaries, plan sponsors, manufacturers and the government. In its first year, 2025, the demonstration cut the national base beneficiary premium by a uniform $15 a month, capped any single plan’s year-over-year premium increase at $35, and narrowed the risk corridors that limit a sponsor’s gains or losses. For 2026, with sponsors better able to predict costs under the new benefit design, CMS scaled the cushion back: the uniform premium reduction dropped to $10 a month, the year-over-year increase cap rose to $50, and the narrowed risk corridors were eliminated entirely, according to the CMS fact sheet that set the 2026 parameters. Sponsors that skipped the demonstration in 2025 were not permitted to join for 2026, and any sponsor that opted in had to enroll every plan under its standalone contracts, not just its lower-premium offerings. New sponsors entering the standalone market for the first time in 2026, or new plans added by a sponsor that already participated in 2025, were still allowed to opt in — the restriction applied only to established sponsors that had sat out the program’s first year.
Free plan-change checklist: A Medicare plan can change its costs, drugs and doctors for next year even when its name stays the same. Check the changes with the free 2027 review sheet.
Why CMS Says Standalone Plans No Longer Need the Cushion
CMS’s own bid review, released July 28, 2026, states that plan sponsors now have “sufficient experience under the redesigned Part D benefit” to support their bid assumptions without government cushioning. On that basis, the agency says it will discontinue the demonstration at the end of CY 2026 “to return the program to operating under traditional market conditions in CY 2027,” according to the Medicare Part D 2027 National Average Monthly Bid Amount Information fact sheet, issued through CMS’s News and Media Group, whose director, Catherine Howden, is listed as the agency’s contact for the release. The same bid-review process had used a separate lever the year before: in negotiating 2026 bids, CMS said it took “unprecedented action” to reject standalone plan bids that combined outsized premium increases with cuts to benefits, after approving other sponsors’ revised bids once concerns about year-over-year increases were addressed. Retiring the stabilization demonstration removes the automatic premium offset while leaving that bid-negotiation authority in place for future years.
What CMS Has Confirmed About 2027 Premiums, and What Remains Unpublished
The same July 2026 fact sheet that announced the demonstration’s end also carried preliminary bid figures CMS uses internally to calculate the 2027 government subsidy to plans, but those figures are inputs to that calculation rather than the premium any individual enrollee will pay. CMS says it will publish the full 2027 Medicare Advantage and Part D landscape, along with final average premiums, “in mid-to-late September,” once plan offerings are finalized. As of this week, CMS’s newsroom had not posted that landscape release or a specific standalone plan premium figure for 2027; the agency’s most recent newsroom items concerned an unrelated Medicaid drug-payment model and rural health funding, not the Part D landscape. Until CMS publishes that release, no finished dollar premium for 2027 standalone plans exists, and any figure circulating before then reflects a preliminary bid calculation rather than what a member will actually be billed.
The Open Enrollment Window Left to Compare Plans
Because the subsidy ends with the current calendar year, any premium change tied to its removal takes effect on standalone plans starting in January 2027. Medicare’s annual Open Enrollment period, which runs from October 15 through December 7 each year, is the only formal window in which a standalone plan member can switch to a different drug plan, drop standalone coverage for a Medicare Advantage plan that bundles drug benefits, or stay in place after checking next year’s numbers. Each plan sponsor must send current members an Annual Notice of Change describing how the plan’s premium, deductible and drug list are shifting for the coming year, and that notice becomes the most reliable way to see the new cost once the subsidy that shaped the last two years of pricing no longer applies.
Which Drug Plans the Change Reaches, and Which It Skips
The demonstration was never open to every kind of Medicare drug coverage. It applied only to standalone prescription drug plans, the plans people buy separately to pair with Original Medicare, plus employer group waiver plans offered through a former employer or union. Medicare Advantage plans that bundle prescription coverage into a single monthly plan, known as MA-PD plans, sit outside the demonstration because their drug costs are financed through the broader Medicare Advantage bid and rebate structure rather than a standalone bid. CMS’s 2027 rate policies, finalized in its CY 2027 Rate Announcement, note that the agency continues calculating separate normalization factors for MA-PD and standalone plan populations, underscoring that the two markets are priced on separate tracks even as one loses its temporary cushion.
Comparing Drug Plans Before the Deadline
The end of the premium cushion means every standalone Part D sponsor is free to set next year’s bid without the government offset that shaped pricing in 2025 and 2026. That shift lands during the same Open Enrollment window when plan members must decide whether to stay in a standalone drug plan or switch. Comparing next year’s premium, deductible and drug list against a current plan takes more than reading the Annual Notice of Change on its own.
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, along with a prescription-by-plan comparison and the Open Enrollment calendar.
See the plan-by-plan cost comparison and the Open Enrollment calendar in The 2027 Medicare Open Enrollment Decision Kit.
This article was researched and drafted with the assistance of AI and reviewed by an editor.
David M. Keller is a finance writer based in Columbus, Ohio, covering personal finance and consumer-focused economic topics. He earned his degree in journalism from Ohio University and began his career reporting on local business and economic trends for a regional media outlet. Since then, he has contributed to a variety of online publications, focusing on clear, practical coverage of topics such as cost of living, debt, and everyday financial decision-making.
