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What drugs are not covered by Medicare Part D?

Some categories are excluded by law, others are simply off your plan's list. The difference determines whether you can do anything about it.

Updated August 17, 2026 · 2 min read

There are two different reasons a drug is not covered, and they lead to completely different responses. One you can appeal. The other you cannot.

Excluded by law

Federal rules exclude certain categories from Part D entirely. No plan covers these, and no exception request will change it.

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

Some Medicare Advantage plans add coverage for a few of these as a supplemental benefit. That is plan by plan and worth asking about.

Not on your plan's formulary

This is the more common situation and it is fixable. The drug is a legitimate Part D drug, your plan simply does not list it.

Here you have real options.

1. Ask your doctor about a covered alternative. Frequently one works just as well.
2. Request a formulary exception with your doctor's supporting statement. Plans must respond within set timeframes.
3. Appeal a denial. There are several levels and a meaningful share succeed.
4. Switch plans during Annual Enrollment to one that covers it.

See how to check a formulary and request an exception.

Covered, but restricted

A third category looks like non coverage and is not. The drug is on the formulary with conditions attached.

• Prior authorization: the plan must approve before covering
• Step therapy: you must try a cheaper drug first
• Quantity limits: the plan caps the amount per fill

These get resolved with paperwork rather than a plan change. See how prior authorization and step therapy work.

Drugs covered by Part B instead

Some medications are covered but not by Part D. Drugs administered in a clinic, most infusions, most chemotherapy, and certain immunosuppressants 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 confusion is common and it is worth pushing back on.

If you are paying cash

Do not settle into paying cash without trying the exception process first. Cash payments for non covered drugs do not count toward your annual out of pocket cap, so you are spending money that does not move you closer to the ceiling.

Manufacturer assistance programs and pharmacy discount programs can help, but understand they sit outside your plan and outside the cap. See what counts toward the cap.