Analyses Paint Mixed Picture of Stand-Alone PDP Costs in 2025

Premiums for many stand-alone Medicare Part D Prescription Drug Plans will go up moderately in 2025, while the number of PDP options for beneficiaries will drop significantly, according to AIS Health’s analysis of the recently released CMS Medicare Advantage and Part D landscape files.

The Inflation Reduction Act, passed in 2022, ushered in a host of policy changes to the Part D benefit that will take effect in 2025: Most notably, Medicare Part D beneficiaries’ out-of-pocket drug costs will be capped at $2,000 annually and Part D plan sponsors will be responsible for 60% (up from 20%) of any costs their enrollees incur beyond that cap. As a result, the Medicare Part D national average monthly bid amount (NAMBA) is projected to increase by $115, nearly 180%, to $179.45 in 2025.

At the same time that it released the 2025 NAMBA, the federal government unveiled the Part D Premium Stabilization Demonstration, which capped premium increases at $35 per month and applied a $15 reduction to the base beneficiary premium for all participating PDPs. In a fact sheet accompanying the release of the landscape files for 2025, CMS estimated that the Part D premium will decline by $7.45 to $46.50 next year, and the average PDP premium will drop by $1.63 to $40.00.

AIS Health’s analysis of CMS data showed that PDP premiums among the 12 national plans will range from $127.23 for Humana Premier Rx Plan to $2.55 for Centene Corp.’s Wellcare Value Script in 2025. The monthly premium for Wellcare Value Script — the largest PDP by enrollment in 2024 — will increase by $1.81 year over year. AARP Medicare Rx Preferred, offered by UnitedHealth Group, will see its premium drop by $15.75, from $104.94 in 2024 to $89.19 next year.

Meanwhile, the number of PDP options for beneficiaries will drop 26% year over year, from 709 in 2024 to 524 in 2025. That is the lowest number of PDPs available since Part D started in 2006.

A KFF analysis of monthly premiums for PDPs in California also painted a mixed picture: Enrollees in eight of the 16 national PDPs offered in 2024 will see their premiums increase by $35 if they do not switch to a different plan in 2025, while enrollees in six other national PDPs will see a premium reduction. SilverScript SmartSaver, offered by CVS Health Corp.’s Aetna, will no longer be available in 2025 and its enrollees will be switched into Aetna’s sole PDP offering for 2025, SilverScript Choice, unless they choose another plan. Because of the switch, those customers’ monthly premium will see a $35 increase, from $18.60 to $53.60. Without the implementation of the Part D Premium Stabilization Demonstration, premium growth would be even more significant, according to KFF.

Rising premiums and fewer options in the PDP market may lead to substantial enrollment shifts, with more enrollees switching from traditional Medicare to Medicare Advantage Prescription Drug plans, the study suggested.

According to AIS’s Directory of Health Plans, the four largest PDP insurers by market share — Centene, Aetna (under the name SilverScript Insurance Company), UnitedHealth Group and Cigna Healthcare — accounted for almost 80% of enrollment as of September 2024. Centene reported year-over-year membership growth of nearly 49.2%, while Aetna saw a double-digit loss at 19.7%. Both UnitedHealthcare and Aetna reduced their PDP offerings in 2025.

This infographic was reprinted from AIS Health’s biweekly publication Radar on Drug Benefits.