What Is Medicare Part D? What It Costs and Covers

HealthCare Writer

Updated on June 20th, 2024

Reviewed by Diane Omdahl

We aim to help you make informed healthcare decisions. While this post may contain links to lead generation forms, this won’t influence our writing. We follow strict editorial standards to give you the most accurate and unbiased information.


Medicare Part D is prescription drug coverage available to anyone with Medicare. It helps cover the cost of prescription drugs, including many recommended shots or vaccines. Medicare Part D plans are offered by private insurance companies and have different costs and lists of covered drugs. You can join a Medicare drug plan during your Initial Enrollment Period, the Annual Enrollment Period, or during a Special Enrollment Period.

As a Medicare beneficiary, you can enroll in Medicare Part D prescription drug insurance to cover medication costs. In 2024, 44% of enrollees chose a stand-alone plan. Part D covers most generic and brand-name drugs, including insulin for a $35 maximum copayment and vaccines like shingles shots.

What Does Medicare Drug Insurance Cover?

Medicare Part D prescription drug policies vary by which medications they cover and how much you must pay. But even the least expensive prescription drug plans must cover most generic and brand-name drugs and the insulin preparations that people on a Medicare plan generally need. It must cover all or most of the drugs in the following categories:

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  • Anticancer drugs (unless covered by Medicare Part B)
  • Antidepressants
  • Antipsychotic medications
  • Anti-convulsive treatments for seizure disorders
  • HIV/AIDS treatments
  • Immunosuppressant medication

Part D prescription drug plans must also cover vaccines, including shingles shots, which are not covered by Medicare Part B. (The annual flu shot, pneumococcal, and COVID-19 vaccines are covered by Medicare Part B.) In 2024, the Medicare Part D insulin savings program provides insulin medication for a $35 maximum copayment.

What Does Medicare Drug Insurance Not Cover?

In general, Part D plans are not allowed to cover medications for:

  • Anorexia, weight loss or weight gain
  • Cough and colds symptomatic relief
  • Cosmetic purposes
  • Fertility drugs
  • Hair growth
  • Over-the-counter drugs
  • Sexual or erectile dysfunction
  • Vitamins and minerals, except for prenatal vitamins, niacin (when used to treat a condition), and fluoride

Medicare Part D Plan Costs

Premiums vary based on income, with higher earners paying more. According to KFF, the maximum deductible in 2024 is $545. The coverage gap starts at $5,030, with out-of-pocket spending capped at $8,000. The Extra Help program helps people with limited income and resources lower or cut Part D costs. Extra Help is available for those with incomes up to $21,870 (individual) or $29,580 (couple).

You can enroll during the Initial Enrollment Period, Annual Enrollment Period (October 15-December 7), or during a Special Enrollment Period due to specific life events.

Considering a Medicare Part D Plan?

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Considering a Medicare Part D Plan?

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Find a Medicare Drug Plan in Your Area

Use the online Medicare Plan Finder tool for a list of the stand-alone Medicare Part D prescription plans and Medicare Advantage plans with prescription drug coverage available in your ZIP code.

Here are some tips for finding a plan that meets your budget, needs, and preferences:

  • Check the prices: The monthly premium is an important consideration but look at cost-sharing, such as deductibles, coinsurance, and copays. A low premium may cost you more in the long run.
  • Medicare Advantage plans: If you prefer “one-stop shopping” and are willing to choose a plan that limits you to a network of providers, you may have lower premium costs with a Medicare Advantage plan (Part C) with prescription drug coverage.
  • Low-premium plans: If you take no or very few medications, you may want to opt for a low-premium Medicare Part D prescription drug plan. It will still cover most of the drugs that people on Medicare need.
  • Long-term medications: If you are taking specific long-term medications, check their availability and costs in various plans. If the drugs you take are generics, look for plans that charge you little or nothing for these.
  • High spending levels: If you expect large medication expenses, it may pay to look for a plan that extends additional coverage if you reach high spending levels.
  • Preferred pharmacy: When selecting a plan, check to see if they have a convenient preferred pharmacy, where you can often get added savings on prescription drugs.

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  1. U.S. Government Website for Medicare. “Part D late enrollment penalty.” (accessed January 24, 2023).

  2. Juliette Cubanski and Anthony Damico.  “Medicare Part D: A First Look at Medicare Drug Plans in 2023.” KFF, November 10, 2022.

  3. Jeannie Fuglesten Biniek and Meredith Freed. “Medicare Advantage 2023 Spotlight: First Look.” KFF, November 10, 2022.

  4. An Overview of the Medicare Part D Prescription Drug Benefit.” KFF, October 19, 2022

  5. U.S. Government Website for Medicare. “What Medicare Part D drug plans cover.” medicare.gov (accessed January 2023).

  6. Ibid.

  7. U.S. Government Website for Medicare. “End-Stage Renal Disease (ESRD).” (accessed January 24, 2023).

  8. NOTE TO: Medicare Advantage Organizations, Prescription Drug Plan Sponsors, and
    Other Interested Parties. cms.gov. Accessed January 24, 2023.

  9. U.S. Government Website for Medicare. “Yearly deductible for drug plans.” (accessed January 24, 2023).

  10. Kaiser Family Foundation. “Overview of Medicare Part D Prescription Drug Benefit.” kff.org, Nov 13, 2019 (accessed April 2020).

  11. Kaiser Family Foundation.“An Overview of the Medicare Part D Prescription Drug Benefit.” KFF, October 19, 2022.

  12. Social Security Administration. Understanding the Extra Help with Your Medicare Prescription Drug Plan. SSA, 2023. (accessed January 24, 2023).

  13. U.S. Government Website for Medicare. “Find a Medicare plan.” medicare.gov (accessed Apr, 2020).

  14. U.S. Government Website for Medicare. “6 tips for choosing Medicare drug coverage.” medicare.gov (Accessed Apr 2020).