Medicare Part D Enrollment: Key Trends and Updates for 2026
As of February 2026, over 56 million Medicare beneficiaries are enrolled in Part D, the outpatient prescription drug benefit, through either stand-alone prescription drug plans (PDPs) or Medicare Advantage plans that include drug coverage (MA-PDs). This represents a continued shift towards Medicare Advantage, with more than half of Part D enrollees now choosing MA-PDs.
Part D Enrollment Overview (February 2026)
A total of 56.1 million Medicare beneficiaries are enrolled in Part D plans, encompassing both non-group and group plans. Specifically, 31.3 million (56%) are enrolled in MA-PDs, while 24.9 million (44%) are enrolled in PDPs. Centers for Medicare & Medicaid Services (CMS) data indicates this is a slight increase in PDP enrollment as a percentage of total Part D enrollees compared to 2025 (42%).
Growth Trends in Enrollment
Between February 2025 and February 2026, enrollment growth in non-group MA-PDs (including special needs plans or SNPs) exceeded growth in non-group PDP enrollment. Non-group MA-PD enrollment increased by 1 million, while non-group PDP enrollment increased by 0.5 million. PDP enrollment increased by 1.7 million, largely driven by an increase in employer group PDP enrollment.
Notably, enrollment in group MA-PDs declined for the first time since 2010 (-1.2 million), while enrollment in group PDPs increased by the largest amount since 2013 (+1.2 million).
Premium Changes and Plan Availability
The average monthly enrollment-weighted premium for non-group PDPs fell from $39 in February 2025 to $36 in February 2026. This decrease reflects the availability of lower-premium PDPs and a potential shift in enrollment towards more affordable plans. KFF analysis shows that beneficiaries in each state have a choice of between 8 and 12 stand-alone Medicare Part D plans, plus numerous Medicare Advantage drug plans.
As of 2026, there are a total of 360 PDPs offered by 17 different parent organizations across the 34 PDP regions nationwide (excluding territories). This represents a 22% decrease in the number of PDPs compared to 2025 and two fewer parent organizations.
Impact of the Inflation Reduction Act
The Inflation Reduction Act has introduced changes to the Part D benefit, influencing plan availability, premiums, and cost-sharing.
Shifts in Employer-Sponsored Plans
A notable trend is the shift among employer/union groups from offering retiree health benefits through contracts with MA-PDs to contracting separately for medical benefits (through MA-only plans) and prescription drug benefits (through stand-alone PDPs). This strategy allows groups to take advantage of the Part D premium stabilization demonstration and receive additional premium subsidies, which are only available to PDPs.
Key Players in PDP Enrollment Growth
Humana and Centene (sponsor of WellCare PDPs) experienced the largest increases in PDP enrollment between February 2025 and February 2026. This growth is likely due to reduced monthly premiums for some of their PDPs and the availability of low or zero-premium options in several regions. Humana’s PDP enrollment increased by 61%, while Centene’s PDP enrollment increased by 11%.
Looking Ahead
The Medicare Part D landscape continues to evolve, with ongoing shifts in enrollment, premium structures, and plan availability. Beneficiaries are encouraged to carefully review their options each year to ensure they have the coverage that best meets their individual needs and budget.