Medicare Part D is the part of Medicare that covers outpatient prescription drugs. Coverage is delivered by private insurance companies approved by Medicare, either as standalone drug plans that pair with Original Medicare or as drug coverage built into Medicare Advantage plans. Because every plan maintains its own drug list, pricing tiers, and pharmacy network, the same medication can cost very different amounts under different plans. This guide reviews the major Part D plan sponsors in 2026 and explains the concepts, from formularies to coverage phases to Extra Help, that matter most when comparing plans.
1. UnitedHealthcare
UnitedHealthcare offers standalone Part D plans in every region, many co-branded with AARP, alongside the drug coverage built into its Medicare Advantage plans. Its national footprint and broad pharmacy networks make it one of the most frequently compared sponsors during annual enrollment.
2. CVS Health / Aetna (SilverScript)
Aetna’s SilverScript plans, part of CVS Health, are among the largest standalone Part D offerings in the country. The plans naturally integrate with CVS retail pharmacies and mail-order services, and SilverScript has long been a familiar name for people who keep Original Medicare and add a drug plan.
3. Humana
Humana is a long-standing Part D sponsor with standalone plans available nationwide and drug coverage embedded in its Medicare Advantage lineup. It has historically partnered with large pharmacy chains on preferred cost-sharing arrangements, and its mail-order pharmacy, CenterWell, serves members who prefer home delivery.
4. Centene (Wellcare)
Centene sponsors standalone Part D plans under the Wellcare brand in all regions. Wellcare drug plans have often positioned themselves as value-oriented options, and the company’s scale makes its plans widely available whether you live in a metropolitan area or a rural county.
5. Cigna Healthcare
Cigna offers standalone Part D plans across the country in addition to its Medicare Advantage drug coverage. Its plans typically feature tiered formularies with preferred pharmacy pricing, and the company’s pharmacy benefit operations, including Express Scripts, support its drug plan administration.
6. Blue Cross Blue Shield affiliates
Many independent Blue Cross Blue Shield companies sponsor Part D plans in their own states, either as standalone drug plans or within Blue-branded Medicare Advantage plans. Offerings differ by affiliate, so the Blue drug plan available in one state may look quite different from a neighboring state’s.
7. Elevance Health (Anthem)
Elevance Health provides Part D coverage in many states through Anthem Blue-branded plans and its Wellpoint products. Its drug plans are administered with the support of CarelonRx, the company’s pharmacy services arm, and availability varies by region.
8. Kaiser Permanente
Kaiser Permanente includes Part D coverage within its Medicare Advantage plans in the states it serves. Members typically fill prescriptions at Kaiser’s own pharmacies or by mail, which fits the organization’s integrated model of care and coverage under one roof.
9. Mutual of Omaha Rx
Mutual of Omaha, widely known for Medicare Supplement insurance, has also sponsored standalone Part D plans in recent years. Its drug plans appeal to people who already hold a Medigap policy with the company and want to keep their coverage relationships simple, though availability has varied by year and region.
10. Regional and pharmacy-affiliated sponsors
Beyond the national names, some regions have smaller sponsors, including health-system-affiliated insurers and pharmacy-linked plans. These can be competitive for specific drug lists, which is why comparing all plans in your ZIP code, rather than only the biggest brands, is worthwhile every year.
Formularies and drug tiers
Every Part D plan publishes a formulary, the list of drugs it covers. Formularies must include a range of medications in each treatment category, but plans choose which specific drugs to include and may require prior authorization, step therapy, or quantity limits for some of them. Covered drugs are grouped into tiers, commonly preferred generics, generics, preferred brands, non-preferred drugs, and specialty medications, with cost sharing rising by tier. Because two plans can place the same drug on different tiers, the only reliable comparison is to enter your exact prescriptions into a plan-comparison tool and see what each plan would charge.
Pharmacy networks
Part D plans contract with pharmacy networks, and many designate certain chains or independents as preferred pharmacies with lower cost sharing than standard network locations. Mail-order pharmacies are often available for maintenance medications, sometimes with extended-day supplies. Before choosing a plan, it helps to confirm that a pharmacy you find convenient is in the plan’s network, and ideally at the preferred level.
Coverage phases in 2026
Part D coverage works in phases over the calendar year. A plan may apply an annual deductible, up to a federally set maximum, before cost sharing begins. In the initial coverage phase, you pay copayments or coinsurance according to your plan’s tiers. Under the redesign introduced by federal law, annual out-of-pocket spending on covered Part D drugs is capped, and once you reach the cap you pay nothing more for covered drugs for the rest of the year; the older coverage gap commonly called the donut hole no longer functions the way it once did. Enrollees can also opt into a program that spreads out-of-pocket drug costs across monthly payments. Exact deductible and cap amounts are set each year, so check current figures when comparing plans.
Extra Help for people with limited income
Extra Help, also called the low-income subsidy, is a federal program that lowers Part D premiums, deductibles, and copayments for people with limited income and resources. Eligibility rules were expanded in recent years so that qualifying individuals receive the full subsidy. People who qualify for both Medicare and Medicaid, or who receive Supplemental Security Income, are generally enrolled automatically, while others can apply through the Social Security Administration. Many state pharmaceutical assistance programs also help residents with drug costs, and drug manufacturers’ patient assistance programs may be available for specific medications, so it is worth checking more than one avenue if costs are a concern.
Enrollment timing and the late enrollment penalty
Part D has its own timing rules. You can first enroll during your initial enrollment period around your 65th birthday or when you otherwise become eligible for Medicare, and you can switch plans each year during the fall open enrollment period, with changes taking effect January 1. Going without Part D or other creditable drug coverage, such as coverage from an employer or the Department of Veterans Affairs, for 63 or more consecutive days after your initial window can trigger a late enrollment penalty that is added to your premium for as long as you have Part D. People with creditable coverage should keep the notices their plan sends each year as proof.
How to choose a Part D plan
List every prescription you take, including dosage and quantity, then compare plans in your area using the official plan finder at Medicare.gov, which estimates your total yearly cost under each plan, including premiums and cost sharing at your chosen pharmacy. To see whether you qualify for Extra Help, review the program details at SSA.gov. A SHIP counselor or licensed insurance agent can walk through the comparison with you at no charge.
Final thoughts
The best Medicare Part D prescription plan is the one that covers your specific medications at the lowest total yearly cost through a pharmacy you can conveniently use. Sponsors adjust formularies, tiers, and networks every year, so a plan that fit well last year may not be the best match now. Reviewing your options each annual enrollment period, with your current drug list in hand, is the most reliable way to keep coverage aligned with your needs in 2026.
Disclaimer
This article is for general informational purposes only and is not medical, financial, legal, or enrollment advice. This site is not connected with or endorsed by the U.S. government or the federal Medicare program. Plan availability, formularies, networks, and cost-sharing rules vary by location and change annually. Always verify current details on Medicare.gov or with a licensed insurance agent or SHIP counselor before making enrollment decisions.