What drugs are covered by Medicare Part D?

Editorial team Published on

There is no single master list of all drugs covered by Medicare Part D because each private insurance plan maintains its own unique list of covered medications, called a formulary.

However, Medicare requires every Part D plan to cover a wide range of prescription drugs, including at least two drugs in the most commonly prescribed categories.

Protected Drug Classes

Part D plans must cover "all or substantially all" medications in six protected classes:

  • Antidepressants
  • Antipsychotics
  • Anticonvulsants (for seizures)
  • Immunosuppressants (for organ transplants)
  • Antiretrovirals (for HIV/AIDS)
  • Anticancer medications (chemotherapy)

Standard Exclusions

By law, Medicare Part D plans do not cover certain types of drugs, including those used for:

  • Weight loss or weight gain
  • Erectile dysfunction
  • Cosmetic purposes or hair growth
  • Fertility
  • Prescription vitamins and minerals (with rare exceptions like prenatal vitamins)
  • Over-the-counter drugs

How to Find Your Specific Drug Coverage

To check if a specific medication is covered, you must look up the exact formulary for your plan using the official Medicare Plan Finder or by reviewing your plan's annual drug list.

What is the best Medicare Part D drug plan for seniors?

The best Medicare Part D plan depends entirely on the specific medications you take, your preferred local pharmacies, and your local ZIP code.

📊 Top National Medicare Part D Providers

National evaluations highlight several leading carriers for 2026 based on cost, coverage, and customer satisfaction:

  • ✅ UnitedHealthcare (AARP)
    • Best for low average deductibles and wide availability.
    • Includes access to Optum home delivery and $0 tiers for common generic drugs.
  • ✅ Humana
    • Best for $0-premium options and low out-of-pocket drug costs.
    • Offers extensive zero-copay structures across basic tiers in many states.
  • ✅ Wellcare
    • Best for budget-conscious shoppers looking for minimal monthly premiums.
    • Features highly affordable generic options via its Value Script plans.
  • ✅ Aetna (SilverScript)
    • Best for specialized chronic condition perks like insulin savings.
    • Maintains strong customer service ratings despite slightly higher average deductibles.

💡 Key Cost Rules for 2026

  • Out-of-Pocket Maximum: Annual out-of-pocket spending on covered prescription drugs is capped at $2,100 for 2026. Once met, you enter catastrophic coverage with $0 remaining costs.
  • Deductible Limit: The maximum allowable annual deductible for a Part D plan is set at $615.
  • All-In Pricing: Always add up the annual cost of the monthly premium plus your estimated medication copays rather than choosing a plan based on the premium alone.

What medications are not covered by Medicare Part D?

Medicare Part D plans do not cover over-the-counter drugs, cosmetic medications, weight-loss or weight-gain drugs, and medications already covered under Medicare Part A or Part B.

Universally Excluded Categories

By federal law, Medicare does not allow Part D plans to cover specific classes of drugs:

  • Over-the-counter (OTC) products: Cold remedies, standard supplements, and non-prescription items.
  • Weight management: Drugs used for weight loss, weight gain, or treating anorexia (except for specific wasting conditions like HIV/AIDS or cancer).
  • Cosmetic and hair growth: Prescriptions like Propecia, Rogaine, or Botox used strictly for appearance.
  • Sexual dysfunction: Erectile dysfunction medications such as Viagra or Cialis.
  • Fertility: Medications that promote fertility, such as Clomid.
  • Vitamins and minerals: Prescription-strength vitamins and mineral products (with limited exceptions for prenatal vitamins and fluoride preparations).

Other Uncovered Prescriptions

  • Part A or Part B drugs: Medications that are already paid for under other parts of Medicare (such as drugs administered during a hospital stay or certain doctor-administered injections).
  • Non-formulary drugs: Each private Part D plan maintains its own approved list of covered medications called a formulary. If a specific prescription is not on your particular plan's list, it is not covered unless you request an official exception.
  • Non-FDA-approved drugs: Products not approved by the U.S. Food and Drug Administration or unproven experimental treatments.

Is Medicare D worth it?

Medicare Part D is generally worth it if you take regular prescription medications or want to protect yourself against high, unexpected drug costs.

Financial Protections and Benefits

  • Out-of-Pocket Cap: In 2026, total out-of-pocket spending on covered prescription drugs is capped at $2,100. Once you reach this limit, you pay $0 for covered drugs for the rest of the year.
  • Payment Plans: The voluntary Medicare Prescription Payment Plan allows you to spread out-of-pocket costs into monthly payments across the calendar year rather than paying a large sum at the pharmacy all at once.
  • Insulin and Vaccines: Recommended adult vaccines have zero cost-sharing, and monthly copays for covered insulin are capped at $35.

Costs to Expect

  • Premiums and Deductibles: The average monthly premium for a standalone Part D plan is $34.50 in 2026, though prices vary by plan and some states offer $0-premium options. Annual deductibles can reach a maximum of $615. High-income earners may pay an extra charge called IRMAA.
  • Late Enrollment Penalties: If you go 63 days or more without creditable prescription drug coverage after becoming eligible, you can face a permanent late enrollment penalty added to your monthly premium.

When It Might Not Seem Worth It

  • If you currently take no prescription medications, paying a monthly premium for a plan you do not use can feel like an unnecessary expense.
  • However, many people still enroll in a low-cost or $0-premium plan to avoid future late enrollment penalties and maintain a safety net for unexpected health changes. You can review 5 Things You May Not Know About Medicare Part D Costs for more details.

What is the most expensive drug for Medicare?

The single medication that costs Medicare the highest total amount overall is the blood thinner Eliquis (apixaban), with total spending reaching over $12 billion to $20 billion annually.

Highest Total Spending (Part D and Part B)

  • Eliquis (apixaban): Costs Medicare the most in total aggregate Part D spending (used for preventing blood clots and strokes).
  • Eylea: Tops Medicare Part B spending for provider-administered drugs, costing billions for macular degeneration treatments.

Highest Cost Per Patient / Per Claim

When looking at the highest cost per user or per prescription claim rather than total national spending:

  • Specialty oncology and biologic drugs like ibrutinib (Imbruvica) and ustekinumab cost upwards of $110,000 to $130,000 per patient annually before recent price negotiations.
  • Certain specialty generics like lenalidomide (a Revlimid generic for blood cancer) cost nearly $14,000 per single prescription fill, making it the most expensive generic burden on the system.

What you need to know about 2026 Medicare Part D prescription drug deductibles

9 related questions found

What are the 10 prescription drugs that Medicare negotiated a better price for?

The first 10 prescription drugs subject to Medicare-negotiated Maximum Fair Prices, effective January 1, 2026, include treatments for conditions such as cardiovascular disease, diabetes, immunology, and oncology. The full list of medications along with their primary indications can be found in the referenced sources, and further details are available in the official CMS Guidance on Selected Drugs and Negotiated Prices.

Is GoodRx better than Medicare Part D?

GoodRx is not "better" than Medicare Part D overall because GoodRx is a discount coupon program, not insurance.

Key Differences

  • Medicare Part D is health insurance. It protects you against catastrophic costs, covers expensive brand-name and specialty medications, and includes an annual out-of-pocket spending cap ($2,100).
  • GoodRx is a free price-comparison and coupon tool. It does not replace insurance and does not count toward your Medicare deductible or out-of-pocket maximum.

When GoodRx is Better

  • Cheap Generic Drugs: GoodRx often beats insurance copays for low-cost generic medications.
  • Uncovered Drugs: If a prescribed medication is not on your Part D plan's formulary (list of covered drugs), GoodRx can lower the cash price.
  • Before Meeting Deductibles: If your Part D plan has a deductible and the cash price with GoodRx is lower than what you would pay out of pocket initially.

When Medicare Part D is Better

  • Brand-Name and Specialty Drugs: GoodRx offers very little savings on expensive brand-name drugs, which can cost thousands of dollars a month and easily bankrupt a cash-pay patient.
  • Safety Net: Part D caps your annual out-of-pocket spending, whereas GoodRx offers no yearly cap or protection if you develop a severe, expensive health condition. Dropping Part D entirely also risks permanent late-enrollment penalties.

You cannot combine GoodRx and Medicare Part D at the register; you must choose to run a prescription through either your insurance or as a cash transaction using GoodRx. Many beneficiaries keep a Part D plan for major protection while spot-checking GoodRx for cheaper generic fills.

Is it better to have Medicare Part C or Part D?

Whether Medicare Part C or Part D is better depends on whether you want an all-in-one health plan or just prescription drug coverage to add to Original Medicare. You generally do not choose between them as direct alternatives because they serve different purposes. Instead, you choose between Original Medicare (with or without a stand-alone Part D plan) and a Medicare Advantage (Part C) plan.

Medicare Part C (Medicare Advantage)

Medicare Part C is an alternative to Original Medicare (Parts A and B) offered by private companies approved by Medicare.

  • What it covers: Combines Part A (hospital), Part B (medical), and usually Part D (prescription drugs) into a single plan. Many plans also add extra benefits like vision, dental, and hearing.
  • Pros: Often features low or $0 monthly premiums, includes out-of-pocket spending caps, and bundles extra services.
  • Cons: Usually restricts you to specific provider networks and may require prior authorizations for treatments.

Medicare Part D

Medicare Part D is a stand-alone prescription drug plan.

  • What it covers: Outpatient prescription medications only.
  • Pros: Designed to be added if you keep Original Medicare (Parts A and B) and need help paying for medications. You can also pair Original Medicare with a Medigap (supplements) policy, though Medigap cannot be combined with Part C.
  • Cons: Does not cover general medical care, hospital visits, or extra perks like dental and vision.

Which Should You Choose?

  • Choose Part C (Medicare Advantage) if you want an all-in-one package with extra vision or dental benefits and do not mind using a defined local network of doctors.
  • Choose Part D if you prefer to stay on Original Medicare (allowing you to see any doctor that accepts Medicare nationwide) and only need a separate policy to cover prescriptions.

You can learn more about weighing these options through the National Council on Aging Pros and Cons Guide or the official Medicare Basics Page.

What 5 medications do doctors say not to take?

Doctors often recommend getting rid of or avoiding specific over-the-counter and routine medications because new evidence shows they are ineffective or carry unnecessary risks.

Based on recent medical guidance highlighted by physicians (such as recent recommendations featured by the Washington Post), here are 5 medications doctors frequently advise reconsidering or dropping from your medicine cabinet:

1. Oral Phenylephrine

  • What it is: A common oral decongestant found in many over-the-counter cold, flu, and sinus products (like certain versions of Sudafed PE or DayQuil).
  • Why doctors say to avoid it: The FDA determined that oral phenylephrine is completely ineffective as a nasal decongestant.
  • What to do instead: If you need a real oral decongestant, ask a pharmacist for pseudoephedrine from behind the pharmacy counter, which actually works.

2. Diphenhydramine (Benadryl)

  • What it is: A first-generation antihistamine widely used for allergies and sleep.
  • Why doctors say to avoid it: Especially for adults over 65, it causes severe side effects like heavy daytime grogginess, confusion, high risk of falls, and trouble urinating. Chronic use has also been linked to cognitive decline.
  • What to do instead: Switch to newer, safer second-generation antihistamines like loratadine (Claritin) or cetirizine (Zyrtec).

3. Daily Low-Dose Aspirin (for Primary Prevention)

  • What it is: Taking a daily aspirin to prevent a first heart attack or stroke.
  • Why doctors say to avoid it: Updated guidelines advise against starting daily aspirin if you have never had a cardiovascular event, because the risk of dangerous stomach bleeding often outweighs the preventative benefits. (Note: If you already take it under strict doctor's orders for an existing heart condition, do not stop without talking to them).
  • What to do instead: Talk to your physician to re-evaluate your personal risk factors and see if a daily aspirin is still appropriate for you.

4. Docusate Sodium (Colace)

  • What it is: A widely sold over-the-counter stool softener.
  • Why doctors say to avoid it: Robust clinical trials have shown it is largely ineffective as a standalone treatment for constipation.
  • What to do instead: Increase your intake of water and try a natural fiber supplement or osmotic laxative if recommended by your care team.

5. Old Codeine Cough Syrup

  • What it is: Prescription opioid-based cough medicine kept in home medicine cabinets.
  • Why doctors say to avoid it: Studies show codeine cough syrup performs no better than a placebo for suppressing coughs, but carries serious risks of dependence, accidental misuse, and dangerous slowed breathing.
  • What to do instead: Safely dispose of leftover prescription narcotics through a community drug take-back program.

Which Medicare drugs will be affected by negotiated drug prices in 2026?

The first 10 Medicare Part D brand-name drugs with negotiated Maximum Fair Prices officially went into effect on January 1, 2026.

💊 The 10 Negotiated Drugs for 2026

  • Eliquis (blood thinner)
  • Jardiance (diabetes/heart failure)
  • Xarelto (blood thinner)
  • Januvia (diabetes)
  • Entresto (heart failure)
  • Stelara (psun/Crohn's)
  • Imbruvica (blood cancer)
  • NovoLog / Fiasp (insulin products)
  • Farxiga (diabetes/kidney/heart)
  • Enbrel (rheumatoid arthritis)

📊 Price Reductions & Savings

  • Discounts: Ranging from 38% to 79% off 2023 list prices.
  • Highest cut: Januvia (79% off).
  • Lowest cut: Imbruvica (38% off).

⚠️ What to Know at the Pharmacy

  • Not a flat copay drop: Your actual out-of-pocket cost depends on your specific Part D plan’s deductible and tier structure.
  • Cap on costs: Total out-of-pocket prescription spending for Part D enrollees is capped at $2,100 in 2026.
  • Future rounds: Additional drugs selected in later cycles take effect in 2027 and 2028.