Millions of people enrolled in a stand-alone Medicare drug plan are about to lose a subsidy cushion many never knew was holding their premium down. The Centers for Medicare & Medicaid Services has confirmed it will let a two-year support program for those plans expire at the end of 2026, clearing the way for the same market pricing rules that applied before the subsidy existed. The timing lands weeks before Medicare’s fall enrollment window opens, leaving a tighter stretch to compare 2027 options before the new pricing takes hold.
The Part D Premium Stabilization Demonstration Ends After Two Years
The program at the center of the change is the Part D Premium Stabilization Demonstration, a voluntary arrangement CMS created in 2025 for standalone prescription drug plans. It was designed to smooth out the premium volatility that followed a redesign of the Medicare drug benefit under the Inflation Reduction Act, one that capped out-of-pocket drug spending for enrollees but shifted more of the financial risk for high-cost claims onto the insurers that sell standalone coverage.
CMS confirmed in a fact sheet dated July 28, 2026 that it will discontinue the demonstration at the end of calendar year 2026, saying plan sponsors have gained sufficient experience pricing the redesigned benefit and no longer need the extra support. The same announcement set the 2027 national base beneficiary premium, the statutory starting point insurers use to build their own plan premiums, at $41.33, and set the national average monthly bid amount insurers submit to CMS, used to calculate federal subsidy payments, at $296.05. A separate, permanent provision in the same law caps how fast that base premium can climb even without the demonstration in place, limiting its annual increase to no more than 6 percent through 2029.
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.
Free download from RetireShield. Getting it also signs you up for the free Retirement Money Brief, a weekday email. Unsubscribe anytime.
Two Guardrails That Softened Premiums Are Gone for 2027
The demonstration worked by adjusting two levers insurers rely on to price standalone plans: it reduced the base beneficiary premium and capped how much any single plan’s premium could increase from one year to the next. In the program’s first year, that meant a $15 reduction to the base premium and a $35 ceiling on premium growth; for 2026 those protections were scaled back to a $10 reduction and a $50 cap, according to an analysis published by KFF. Neither guardrail carries into 2027, so a plan’s premium can move by whatever amount its bid supports.
The subsidy was not inexpensive to run. It totaled $9.8 billion in federal spending across 2025 and 2026, the KFF analysis found, and in exchange it reduced the average monthly premium for standalone drug plans by $26 in 2025 and $16 in 2026, based on Medicare Payment Advisory Commission figures cited in the same piece. Enrollment in standalone plans grew from 22.8 million people in 2024 to 24.9 million in 2026 while the subsidy was in place, evidence the extra support was doing what it was designed to do.
For a household budgeting around a fixed monthly income, the arithmetic that mattered in 2026 is gone along with the program. The $10 cushion built into the base premium and the $50 ceiling on how far any single plan’s price could jump both disappear at once, so a standalone plan’s 2027 premium is simply whatever its bid produces once CMS locks in the numbers, with no federal floor softening the result.
Standalone Plans Already Cost About Four Times More Than Medicare Advantage Drug Coverage
Even with the subsidy propping up standalone premiums, the average monthly premium for a stand-alone Part D plan in 2026 ran more than four times higher than the average premium for drug coverage bundled into a Medicare Advantage plan, $36 versus $8, a gap the KFF analysis attributes to the rebate dollars Medicare Advantage insurers can use to buy down their own drug premiums in ways standalone plans cannot. That price difference is one reason some beneficiaries weigh switching from standalone coverage to a Medicare Advantage plan, though the tradeoffs involve provider networks and drug formularies, not premiums alone.
The same analysis points to forces beyond the subsidy’s expiration that will keep pushing standalone premiums higher regardless: rising drug prices and growing use of GLP-1 medications and other expensive specialty drugs are adding cost pressure that the demonstration was never designed to solve. That pressure is expected to continue into 2027 and beyond, subsidy or no subsidy, meaning next year’s bids are unlikely to be the last to climb.
Comparing Plans Before the October 15 Enrollment Window Opens
The Medicare Open Enrollment period for 2027 coverage runs from October 15 through December 7, giving beneficiaries their annual chance to join, drop or switch a Medicare drug plan or Medicare Advantage plan before changes take effect on January 1. Medicare’s own Plan Finder tool lets a household enter a ZIP code, current prescriptions and preferred pharmacy to see how each available plan’s premium, deductible and drug costs would apply once the new pricing is loaded into the system, which typically happens by the time the window opens.
CMS said in its fact sheet that it will publish the full 2027 Medicare Advantage and Part D landscape, including plan-specific premiums, in mid-to-late September, the first point at which households will see exactly what the subsidy’s expiration means for their own plan rather than the national averages released so far.
Reading the 2027 Numbers Once CMS Publishes Them
CMS’s mid-to-late September landscape release will show the base numbers behind the higher 2027 bids, but it will not tell any one household what its own plan will actually charge once the demonstration’s discount disappears from the formula. Each standalone plan sets its final premium inside that same redesigned Part D benefit, and a plan that raises its price is not required to flag whether a cheaper option nearby still covers the same drugs and doctors. That comparison has to happen manually, in the same weeks the new numbers are still being finalized.
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 comparison in The 2027 Medicare Open Enrollment Decision Kit.
AI-assisted research and drafting; reviewed by an editor.
