KFF Analysis: Most Part D Enrollees Face Under $10 Premium Hikes for 2027, But Some Could See $50+ Increases

Most people enrolled in a Medicare Part D stand-alone prescription drug plan will see their monthly premium rise by less than $10 in 2027, but enrollees who stay in certain plans without comparing options could face increases of $50 a month or more, according to a brief published October 2, 2026, by KFF, a nonpartisan health policy research organization. Medicare Part D stand-alone drug plans, often called PDPs, are prescription drug coverage sold separately from Medicare Advantage plans and are typically paired with Original Medicare.

The KFF brief also found a modest reduction in the number of PDPs available nationwide for 2027, continuing a trend of insurers narrowing their Part D offerings in recent plan years. For readers weighing drug coverage for the year ahead, the core message from KFF's analysis is straightforward: the plan you're in today may not be the plan with the smallest premium increase for 2027, and the only way to know is to compare your options before the end of this year's enrollment window.

Why Premium Changes Vary So Much From Plan to Plan

Part D premiums are set by each insurer based on that specific plan's projected drug costs, benefit design, and enrollment, not by a single nationwide rate. That structure is why KFF's analysis found such a wide range for 2027: some plans will raise premiums only modestly, in line with overall drug cost trends, while others will raise them sharply, often because an insurer is correcting course after a period of unsustainably low pricing or because enrollment shifts have left fewer healthy members to spread the plan's costs.

The enrollees most exposed to the larger increases KFF describes, $50 or more per month, are typically those who stay in the same plan year after year without checking whether a lower-cost option still covers their medications. Medicare's rules automatically re-enroll most Part D members into their current plan if they take no action, which means inertia, rather than necessity, is often what drives someone into a steep premium increase.

This variation plays out against a backdrop that hasn't changed for 2027: since 2025, a provision of the Inflation Reduction Act has capped annual out-of-pocket prescription drug costs for Part D enrollees at $2,000. That cap limits what enrollees pay at the pharmacy counter, but it does not limit the monthly premium an insurer charges, which is the cost KFF's new analysis focuses on. A lower out-of-pocket cap does not protect someone from a premium increase if they don't compare plans.

Key Takeaway

Medicare's Open Enrollment Period for 2027 coverage runs October 15 through December 7, 2026. KFF's analysis indicates that comparing Part D plans during this window, rather than letting a current plan auto-renew, is the main way to avoid the larger premium increases described in its report.

What Part D Enrollees Should Do Before December 7, 2026

Since KFF ties the risk of a steep premium jump to staying in a plan without checking alternatives, the most direct response is to compare plans during this year's Open Enrollment Period, which runs from October 15 through December 7, 2026, for coverage that starts January 1, 2027. A few concrete steps can help:

Re-check your plan's 2027 premium and formulary. Insurers can change both the monthly premium and which drugs are covered each year, so a plan that worked well in 2026 is not guaranteed to still be the best fit for 2027.
Use Medicare's Plan Finder tool at Medicare.gov or call 1-800-MEDICARE to compare 2027 Part D options side by side using the specific medications you take.
Watch for plans exiting the market. KFF notes a modest reduction in the number of available PDPs for 2027, so some enrollees whose current plan is discontinued may be moved into a different plan automatically, making a direct comparison even more important this year.
Talk to a licensed insurance agent if you want help interpreting premium, deductible, and copay differences across plans. Senior Plan Path does not provide personalized financial or medical advice, but a licensed agent can walk through your specific drug list and budget with you.

KFF's full brief, including plan-by-plan premium data and methodology, is available at kff.org.