What Does Medicare Cover for Prescriptions
Medicare prescription coverage is one of the most misunderstood parts of the program. Many beneficiaries assume their hospital or medical plan automatically pays for their medications. That assumption can lead to surprise bills at the pharmacy counter. Understanding what Medicare covers for prescriptions is essential for managing your health and your budget. The answer depends on which part of Medicare you have, whether you added a separate drug plan, and the specific medication you need.
Medicare is divided into parts that each handle different services. Original Medicare, which includes Part A and Part B, does not cover most outpatient prescription drugs. Part A covers medications you receive during a hospital stay. Part B covers a limited set of drugs, such as those administered in a doctor’s office or through infusion. For everyday prescriptions you pick up at a pharmacy, you need a standalone Part D plan or a Medicare Advantage plan that includes drug coverage. This layered system can be confusing, but once you understand the structure, you can make informed choices.
In this article, we break down exactly what Medicare covers for prescriptions, from hospital-administered drugs to mail-order refills. We explain the coverage gaps, the costs you can expect, and the steps you can take to lower your out-of-pocket expenses. Whether you are new to Medicare or reviewing your options during the annual enrollment period, this guide will help you navigate prescription coverage with confidence.
Medicare Part A and Part B Prescription Coverage
Medicare Part A (hospital insurance) covers prescription drugs that are part of your inpatient care. If you are admitted to a hospital or skilled nursing facility, the medications you receive during that stay are included under Part A. This includes drugs administered by nurses or doctors, intravenous medications, and certain oral medications used immediately before or after surgery. You do not pay separately for these drugs; they are bundled into your overall Part A benefit. However, once you are discharged, any prescriptions you need to fill at a retail pharmacy fall outside Part A coverage.
Medicare Part B (medical insurance) covers a narrower set of prescription drugs. These are typically drugs that are administered by a healthcare provider, such as injections, infusions, and certain oral cancer medications. Examples include chemotherapy drugs, immunosuppressants after an organ transplant, and injectable osteoporosis medications. Part B also covers some vaccines, including the flu shot, pneumonia shot, and hepatitis B shot. Drugs you self-administer at home, like insulin or blood pressure pills, are generally not covered by Part B. For a complete understanding of hospital cost sharing, read our guide on Does Medicare Cover 100 Percent of Hospital Bills.
Medicare Part D: Outpatient Prescription Drug Coverage
Part D is the Medicare program that covers outpatient prescription drugs. It is available as a standalone plan that you add to Original Medicare (Parts A and B) or as part of a Medicare Advantage plan (Part C) that bundles medical and drug coverage. Part D plans are offered by private insurance companies approved by Medicare. Each plan has its own list of covered drugs, called a formulary, and its own cost-sharing structure.
Part D coverage is not automatic. You must enroll during your Initial Enrollment Period or during the annual Open Enrollment Period (October 15 to December 7). If you delay enrollment and do not have other creditable drug coverage (such as from an employer or union), you may pay a late enrollment penalty. This penalty is added to your monthly premium for as long as you have Part D.
How Part D Formularies Work
Each Part D plan organizes its formulary into tiers. Lower-tier drugs (Tier 1) are usually generic medications with the lowest copayments. Higher-tier drugs (Tier 3, Tier 4, and Tier 5) include brand-name and specialty drugs with higher cost-sharing. Plans can change their formularies at any time, but they must notify you in advance if a drug you take is removed or moved to a higher tier. You can request an exception if your doctor believes a drug on a higher tier is medically necessary.
When comparing Part D plans, check the formulary to see if your specific medications are covered. A plan with a low premium may not cover your expensive brand-name drug, leaving you with high out-of-pocket costs. Use the Medicare Plan Finder tool or consult a licensed agent to match your drug list to the best plan.
Part D Coverage Stages and Costs
Part D has four coverage stages each year. Understanding them helps you predict your annual drug costs.
- Deductible Stage: You pay the full cost of your drugs until you reach the plan’s deductible. In 2025, no Part D plan can have a deductible higher than $545. Some plans have lower deductibles or waive them for generic drugs.
- Initial Coverage Stage: After meeting the deductible, you pay a copayment or coinsurance for each drug until your total drug costs (what you and the plan pay) reach $5,030 in 2025.
- Coverage Gap (Donut Hole): Once you reach the initial coverage limit, you enter the coverage gap. In 2025, you pay 25% of the cost for brand-name drugs and 25% for generic drugs in the gap. Manufacturer discounts apply to brand-name drugs to help lower your costs.
- Catastrophic Coverage: After you have spent $8,000 out of pocket in 2025, you enter catastrophic coverage. For the rest of the year, you pay a small copayment or coinsurance (up to $4.90 for generic drugs and $12.15 for brand-name drugs). The Inflation Reduction Act eliminated the 5% coinsurance that previously applied in this stage.
These stages reset every January 1. If you take expensive medications, you may reach catastrophic coverage early in the year. Planning for these costs with a health savings account or by choosing a plan with a lower deductible can reduce financial stress.
Medicare Advantage Plans with Drug Coverage
Medicare Advantage (Part C) plans are an alternative to Original Medicare. These plans are offered by private insurers and must provide at least the same coverage as Parts A and B. Many Medicare Advantage plans also include Part D prescription drug coverage. These are called Medicare Advantage Prescription Drug (MA-PD) plans. When you choose an MA-PD plan, your medical and drug coverage are combined into one plan. You typically have a network of pharmacies and may need to use preferred pharmacies for the lowest costs.
Medicare Advantage plans often use prior authorization, step therapy, and quantity limits to manage drug costs. Prior authorization means your doctor must get approval from the plan before the drug is covered. Step therapy requires you to try a lower-cost drug first before the plan covers a more expensive alternative. Quantity limits restrict the amount of medication you can receive at one time. These utilization management tools can affect how quickly you get your medications, so review the plan’s rules before enrolling.
If you have a Medicare Advantage plan without drug coverage, you cannot join a standalone Part D plan. You would need to switch to Original Medicare during a valid enrollment period to add Part D. To understand how Medicare costs change annually, refer to our article on Does Medicare Cost Go Up Every Year.
Medigap and Prescription Drugs
Medigap (Medicare Supplement Insurance) policies help pay for some of the out-of-pocket costs in Original Medicare, such as deductibles, coinsurance, and copayments. However, Medigap policies sold after 2006 do not include prescription drug coverage. If you have Original Medicare and a Medigap policy, you also need a standalone Part D plan to cover your outpatient medications. Some older Medigap policies (issued before 2006) may offer limited drug coverage, but those are rare and not available for new enrollees.
If you are enrolling in Medicare for the first time, you cannot buy a Medigap policy that covers drugs. Your best approach is to combine Original Medicare with a Part D plan or choose a Medicare Advantage plan with built-in drug coverage. Comparing the total premium and out-of-pocket costs for both options will help you decide which is more affordable for your medication needs.
Drugs Not Covered by Medicare
Medicare explicitly excludes certain categories of drugs from coverage under Part D. These include:
- Drugs used for weight loss or weight gain (unless for a medical condition like cachexia)
- Drugs for erectile dysfunction (when used for sexual enhancement)
- Over-the-counter medications (unless prescribed with a doctor’s order for a specific condition)
- Cosmetic drugs (such as hair growth or wrinkle treatments)
- Vitamins and nutritional supplements (except for specific medical conditions like vitamin D deficiency or prenatal vitamins)
If your doctor prescribes a drug that Medicare does not cover, you may need to pay the full price out of pocket. In some cases, you can use a manufacturer patient assistance program or a discount card to reduce the cost. Always ask your doctor if there is a covered alternative before filling a non-covered prescription.
Extra Help Program for Low-Income Beneficiaries
The Extra Help program, also known as the Low-Income Subsidy (LIS), helps people with limited income and resources pay for Part D costs. Extra Help covers most of your Part D premium, reduces your deductible, and limits your copayments for generic and brand-name drugs. In 2025, if you qualify for Extra Help, you pay no more than $4.90 for generic drugs and $12.15 for brand-name drugs. You also do not have a coverage gap.
To qualify for Extra Help, your income must be below 150% of the federal poverty level and your resources (savings, stocks, and bonds) must be below a certain limit. You can apply through the Social Security Administration or through your state’s Medicaid office. If you are already enrolled in Medicaid, Medicare Savings Program, or Supplemental Security Income (SSI), you automatically qualify for Extra Help.
How to Choose the Right Prescription Coverage
Choosing the right prescription coverage requires a careful review of your current medications and your budget. Follow these steps to find the best plan for your needs.
- Make a list of all medications you take, including the dosage and frequency. Include over-the-counter drugs if your doctor recommends them for a medical condition.
- Check the formulary of each Part D or Medicare Advantage plan available in your area. Use the Medicare Plan Finder tool or work with a licensed agent to see which plans cover your drugs.
- Compare the total annual cost, including premiums, deductibles, and copayments for your specific drugs. Do not choose a plan based on premium alone; a low-premium plan may have high copayments for your medications.
- Review the pharmacy network. If you use a specific pharmacy, make sure it is in the plan’s network. Some plans offer lower copayments at preferred pharmacies.
- Check for utilization management restrictions. If your drug requires prior authorization or step therapy, find out how to get approval before you enroll.
Once you select a plan, you can enroll during the Initial Enrollment Period (when you first become eligible for Medicare), the Annual Enrollment Period (October 15 to December 7), or a Special Enrollment Period (if you experience a qualifying life event like moving or losing employer coverage). For more details on hospice medication coverage, see our article on Does Medicare Cover 24-Hour In-Home Hospice Care.
Frequently Asked Questions
Does Medicare cover insulin?
Yes, Medicare Part D covers insulin and certain supplies needed to administer it. In 2025, the Inflation Reduction Act caps the cost of a one-month supply of each insulin product at $35 for Part D plans. Medicare Advantage plans with drug coverage also must comply with this cap. Part B covers insulin used with an insulin pump.
Can I change my Part D plan after enrollment?
You can change your Part D plan during the Annual Enrollment Period (October 15 to December 7) each year. You can also switch during a Special Enrollment Period if you experience a qualifying event, such as moving to a new area or losing other drug coverage. If you have a Medicare Advantage plan, you can switch to a different MA-PD plan or return to Original Medicare with a Part D plan during the Medicare Advantage Open Enrollment Period (January 1 to March 31).
Does Medicare cover mail-order prescriptions?
Most Part D and Medicare Advantage plans offer mail-order pharmacy options for maintenance medications. Mail-order pharmacies typically provide a 90-day supply at a lower cost than retail pharmacies. Check your plan’s network to see which mail-order pharmacies are approved. Some plans require you to use their preferred mail-order pharmacy for the best price.
What happens if my drug is not on the formulary?
If your drug is not on your plan’s formulary, you have several options. You can request a formulary exception from your plan. Your doctor must provide a statement explaining why the drug is medically necessary and why alternatives on the formulary are not suitable. If the exception is denied, you can appeal the decision. Alternatively, you can ask your doctor to prescribe a similar drug that is on the formulary, or you can switch to a different Part D plan during the next open enrollment period that covers your medication.
For information on mammogram coverage with Medicare, read our article on Does Medicare Cover 3D Mammograms.
Understanding what Medicare covers for prescriptions is the first step to controlling your healthcare costs. By reviewing your drug list, comparing plans, and using assistance programs like Extra Help, you can ensure you have affordable access to the medications you need. Medicare prescription coverage is complex, but with the right information and support, you can make a confident choice that protects both your health and your finances. Start your plan comparison today to see which option works best for your situation.
