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What drugs are not covered by Medicare Part D?

Some drugs are left out of Part D by federal law, and no plan covers them. Others are just missing from your plan's list, and those you can ask the plan to cover.

Updated September 3, 2026 · 3 min read · by Gerino Alejos

Part D leaves out two kinds of drugs. Some are excluded by federal law, and no plan covers them. Others are ordinary Part D drugs that your plan just does not list, and those you can ask the plan to cover.

Excluded by law

No plan covers these, and asking for an exception will not change it.

• Drugs for weight loss or weight gain, though this area has been changing and is worth asking about
• Drugs for cosmetic reasons or hair growth
• Fertility drugs
• Drugs for erectile dysfunction when prescribed for that purpose
• Over the counter medications
• Vitamins and minerals, with a few prescription exceptions such as prenatal vitamins and fluoride
• Drugs already covered under Part A or Part B

Some Medicare Advantage plans add a few of these as an extra benefit, so ask.

Not on your plan's formulary

This is the more common case, and you can fix it. The drug is a normal Part D drug. Your plan just left it off its formulary, the plan's list of covered drugs and what each one costs.

You have four options.

1. Ask your doctor about a covered alternative. Often one works just as well.
2. Ask the plan for a formulary exception, a request to cover the drug anyway, with a statement from your doctor. Plans must answer within set time limits.
3. If the plan says no, appeal. There are several levels, and a meaningful share of appeals succeed.
4. Switch plans during Annual Enrollment, the fall window when anyone can change plans, to one that covers it.

See how to check a formulary and request an exception.

Covered, but restricted

A third case looks like the drug is not covered, but it is. The drug is on the formulary with conditions attached.

• Prior authorization, which means the plan must approve the drug before it pays
• Step therapy, which means you must try a lower cost drug first
• Quantity limits, which means the plan caps how much it covers per fill

These get sorted out with paperwork, not a plan change. See how prior authorization and step therapy work.

Drugs covered by Part B instead

Some medications are covered, but by Part B, the part of Medicare that pays for doctor visits and outpatient care, rather than by Part D. Drugs given in a clinic, most infusions, most chemotherapy, and certain immunosuppressants, the anti rejection drugs taken after a covered transplant, fall under Part B.

If a pharmacy tells you Part D will not cover something, ask whether it should be billed to Part B. This billing mix up is common.

If you are paying cash

Do not settle into paying cash before you try the exception process. Cash you pay for drugs the plan does not cover does not count toward your yearly out of pocket cap, the limit on what you pay for covered drugs in a year.

Manufacturer assistance programs and pharmacy discount programs can help with the price. Just know that they sit outside your plan and outside the cap. See what counts toward the cap.

Start by asking the pharmacy which of these cases applies to your drug, then call your doctor's office about an alternative or an exception. If you want help sorting it out, call our McAllen office or send us your ZIP code through the form on this page.

Gerino Alejos

Licensed insurance agent · License 3128710 · NPN 18243381

Owner of McAllen Insurance Group, an independent agency on North 10th Street in McAllen. Works with clients across Hidalgo, Cameron and Starr counties on Medicare, Marketplace health, life and auto coverage. Se habla español.