Which drugs are covered by Medicare Part D is a question millions of seniors and retirees ask each year, especially as prescription costs continue to rise. With new updates for 2026, understanding what medications are included in coverage and which are excluded is more important than ever.
Why Knowing Covered Drugs Matters
Medicare Part D does not pay for every prescription available at the pharmacy. Instead, each plan offers a formulary, which is the official list of drugs it covers. These lists vary from plan to plan but must meet federal standards to ensure access to essential medications.
For 2026, all Medicare Part D plans are required to cover drugs across major therapeutic categories, such as cancer treatments, HIV/AIDS medications, mental health prescriptions, seizure-control drugs, and immunosuppressants. Each category must have at least two options, giving patients choices in their treatment.
Key Points Summary
🔹 Fast Facts on Part D Coverage
- Formularies list the drugs each plan covers.
- Coverage includes all major therapeutic drug categories.
- At least two drugs per class are always required.
- Insulin and adult vaccines remain widely covered.
- 2026 introduces a $2,100 out-of-pocket cap on drug costs.
- Cosmetic, fertility, and over-the-counter drugs are excluded.
Categories of Drugs Covered
Here are the main groups of medications included in most Medicare Part D formularies:
- Generic Drugs – Affordable versions of brand-name drugs, usually with the lowest copays.
- Preferred Brand Drugs – Brand-name prescriptions that plans select for lower cost-sharing.
- Specialty Medications – High-cost drugs for chronic or complex conditions like cancer, multiple sclerosis, or rheumatoid arthritis.
- Insulin and Supplies – Covered with a $35 monthly cap, continuing into 2026.
- Vaccines – Includes shingles, Tdap, flu, and other adult vaccines at no cost.
Many plans also cover preventive drugs that help manage chronic illnesses such as heart disease, diabetes, or high blood pressure.
Drugs Not Covered by Medicare Part D
Not every drug is eligible for coverage. Federal law excludes certain medications, including:
- Over-the-counter drugs (cold medicine, vitamins, etc.).
- Weight loss or weight gain drugs.
- Cosmetic treatments like hair growth medications.
- Fertility medications.
- Drugs covered by Medicare Part A (hospital) or Part B (outpatient/doctor administered).
Knowing these exclusions helps avoid unexpected pharmacy bills.
Checking If Your Prescription Is Covered
Because formularies change each year, a drug covered in 2025 may not appear in 2026. Beneficiaries should:
- Review their plan’s updated formulary online.
- Check which tier their drug falls under (generic, brand, or specialty).
- Confirm preferred pharmacy networks for lowest prices.
- Compare plans during the annual open enrollment window (October 15 – December 7).
This process ensures you continue receiving your prescriptions at the most affordable cost.
Major Change in 2026: Out-of-Pocket Cap
The biggest update is the new $2,100 annual out-of-pocket cap for Medicare Part D enrollees. Once this limit is reached, you will not pay anything more for covered prescriptions that year. This change offers significant financial relief for patients requiring expensive specialty drugs.
Combined with the continuing $35 insulin cap and free vaccines, 2026 marks one of the most impactful years in Medicare Part D history.
FAQs
1. Are all prescriptions included in Medicare Part D?
No, only those listed on the plan’s formulary are included, though rules ensure coverage across major drug categories.
2. Is insulin fully covered under Part D?
Yes, insulin remains covered with a $35 monthly maximum cost per prescription.
3. Can a plan stop covering my drug?
Yes, but plans must provide notice and usually offer an alternative in the same drug class.
Knowing which drugs are covered by Medicare Part D can protect your health and your wallet. With the 2026 updates, now is the time to review your plan and make sure your prescriptions are still included. Have you checked your drug list for the coming year?