Stand-Alone Part D Premiums Could Rise to $51 a Month in 2027. Expect Plan Switches Before Dec. 7.
KFF finds 10.4 million stand-alone Part D enrollees face higher 2027 premiums if they stay put, and no zero-premium plans remain. CMS projected $36.
The average monthly premium for a Medicare stand-alone prescription drug plan would rise from $34 in 2026 to $51 in 2027 if enrollees stay in their current plans, according to an Oct. 30 analysis by KFF. Open enrollment runs through Dec. 7.
That is a different picture from the one the Centers for Medicare and Medicaid Services (CMS) gave on Sept. 28, when it projected the average stand-alone premium would rise from about $35 to $36. Both figures can be true. They measure different things.
Why do the two numbers differ?
KFF weights premiums by June 2026 enrollment and assumes people stay in the plan they have. CMS's figure is based on September 2026 enrollment, and KFF says CMS did not explain its method. KFF itself expects the actual 2027 average to come in below $51 because some enrollees will switch. The gap is a measure of how much switching it would take to avoid the increase.
The cause is the end of the Part D Premium Stabilization Demonstration, which paid extra subsidies to stand-alone plans and capped annual premium increases at $50 for 2026. It is gone for 2027. Enrollees in Medicare Advantage drug plans are less exposed: KFF puts their average drug premium at $9 a month in 2027, up by less than $2.
The premium patients see in December is not the change practices will feel. That arrives in January, as new formularies and coinsurance at the pharmacy counter.
Who is affected, by the numbers?
Compiled by the Script Pad from KFF's analysis: of 13.6 million stand-alone enrollees without low-income subsidies, 10.4 million, or 76 percent, face a higher premium if they keep their plan, against 56 percent facing an increase for 2026. That includes 4.1 million people in zero-premium plans; none will exist in 2027. About 2.4 million would see increases of more than $50 a month, compared with about 38,000 last year. Nearly 30 percent, 3.9 million people, would pay $100 or more a month.
The largest plans show the spread. UnitedHealthcare's AARP Medicare Rx Preferred would average $204.50, up from $126, an increase of $78.50 a month, or $942 a year by our arithmetic. Centene's Wellcare Value Script Rx would average $6.50. The standard Part D deductible rises from $615 to $700, about 14 percent. The average deductible in stand-alone plans rises from $540 to $643, and in Medicare Advantage drug plans from $360 to $489.
What changes at the pharmacy counter?
Cost sharing is shifting toward coinsurance. KFF finds 83 percent of Medicare Advantage drug plan enrollees will face coinsurance rather than a flat copay for preferred brands in 2027, up from 54 percent, with a median of 20 percent. Stand-alone plans' median for preferred brands is 25 percent. Centene, whose Wellcare plans hold half of all stand-alone enrollees, is adding a new injectable tier with 15 percent coinsurance.
Coinsurance moves a patient's cost with the drug's price, so patients on expensive brands and injectables will feel the change first, often at the first January fill.
What practices should expect
Patients who switch plans to escape a premium increase will often land on a different formulary. Expect a wave of tier questions, prior authorization requests and therapeutic substitution calls in January, concentrated among older patients on brand-name and injectable drugs. Practices that refill on a fixed schedule can flag Medicare patients on high-cost brands now and suggest they check their drugs in the Medicare Plan Finder before Dec. 7, without recommending a plan.
Our open enrollment piece from Oct. 15 covered the network side of the same season. For employer plans, the Labor Department's new PBM fee disclosure rule addresses a different part of the drug-pricing chain.
Reported, fact-checked and edited by The Script Pad's editorial staff. See How we use AI.
This article is for professional education and does not replace clinical judgment. Treatment decisions should be based on the individual patient and current guidelines.
