On July 28, 2026, the Centers for Medicare & Medicaid Services made two announcements at once: the technical numbers that will set every 2027 Medicare Part D premium, and the end of a subsidy that has quietly held those premiums down for the past two years. The subsidy went to insurers running stand-alone prescription drug plans, and its disappearance is why outside estimates now point to some monthly drug bills rising by double digits next year, even though CMS itself has not published a specific household dollar figure.
What the Premium Stabilization Demonstration Actually Paid For
CMS launched the Part D Premium Stabilization Demonstration for the 2025 plan year, aimed at stand-alone prescription drug plans, known as PDPs, that do not come bundled with a Medicare Advantage plan. The goal was to smooth out premium swings while the Inflation Reduction Act’s redesigned drug benefit was still being phased in — a redesign that eliminated the old coverage gap and capped out-of-pocket drug costs, but also shifted more financial risk onto the insurers that sell PDPs. Rather than let that risk show up immediately as a premium spike, the demonstration gave participating plans a fixed-dollar reduction in the base beneficiary premium and a separate limit on how much any plan’s total premium could rise year to year. The administration had already scaled the subsidy back once, reducing its size for the 2026 plan year, before deciding to end it altogether starting in 2027.
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Why CMS Says the Support Is No Longer Needed
In the fact sheet announcing the change, CMS said its review of the bids insurers submitted for 2027 found that Part D plan sponsors had gained sufficient experience under the redesigned Part D benefit to support their own pricing assumptions. In plain terms: the agency believes insurers have adjusted to the new benefit structure well enough that they no longer need a government cushion to set stable prices, so the demonstration ends at the close of 2026 and the program returns to ordinary market conditions for 2027. Alongside that decision, CMS released the numbers 2027 premiums will be calculated from. The national average monthly bid amount, an enrollment-weighted average of what insurers bid to run the basic Part D benefit, is $296.05 for 2027. The base beneficiary premium, the starting point plans use to set their own premiums, will be $41.33, up from $38.99 in 2026 — a 6 percent increase, the maximum allowed under the law’s premium-stabilization cap through 2029.
The Estimate Behind the “$11 to $20” Number
CMS’s own release does not include a household-level premium estimate; that figure comes from what administration officials told reporters after the announcement. According to the Center for Medicare Advocacy’s account of the rollout, the administration told the Wall Street Journal that about 75 percent of stand-alone drug-plan enrollees will see some premium increase in 2027, with roughly 30 percent facing an increase under $10 a month and 45 percent facing one largely in the $11-to-$20 range a month. CMS Administrator Dr. Mehmet Oz offered a narrower version publicly, saying premiums would rise by less than $10 for most beneficiaries and that some enrollees could even see lower payments. Neither figure is a guarantee for any individual plan; actual 2027 premiums vary by insurer and by state, and CMS has not yet published them.
Why This Falls Hardest on Stand-Alone Plan Members
The premium change targets a specific slice of Medicare, not everyone with drug coverage. Roughly 25 million people get their Part D benefit through a stand-alone prescription drug plan alongside traditional Medicare, rather than through a Medicare Advantage plan that bundles drug coverage with medical coverage. Medicare Advantage insurers can use rebates from the medical side of their plans to buy down or eliminate a drug premium, which is part of why the average Medicare Advantage drug premium has run far below the average stand-alone premium in recent years. Stand-alone plans have no equivalent rebate pool to draw on, which is exactly why CMS built the demonstration around them in the first place, and why ending it lands on that group specifically rather than on the Medicare population as a whole.
What’s Confirmed Now, and What’s Still Coming
Three numbers are locked in from the July 28 release: the $296.05 national bid amount, the $41.33 base beneficiary premium, and a $2 de minimis amount plans can use to keep low-income enrollees from being reassigned. What is not locked in is what any specific stand-alone plan will actually charge a member starting January 1, 2027. CMS says it will publish the full 2027 Medicare Advantage and Part D landscape, the plan-by-plan premiums people compare during Open Enrollment, in mid-to-late September, once every insurer’s final offering is submitted. Until that landscape data is out, the $11-to-$20 range is the best available estimate of what the end of this subsidy means for a monthly bill, not a finished number.
This article was produced with AI assistance and reviewed by a human editor. Figures are linked to their primary sources; where a claim could not be verified from the public record, we say so.
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