Medicare's coverage of weight loss drugs depends on which part of Medicare you have and whether the drug treats a related medical condition

Medicare Part B covers two weight loss medications: semaglutide (Wegovy) and tirzepatide (Zepbound), but only when prescribed to treat type 2 diabetes or heart disease — not for weight loss alone. If your doctor prescribes one of these drugs specifically for diabetes or heart protection, Medicare Part B typically covers 80 percent of the cost after you meet your deductible. You pay the remaining 20 percent.

Medicare Part D (prescription drug coverage) may cover other weight loss medications depending on your specific plan. Each Part D plan maintains its own formulary — the list of drugs it will pay for — so coverage varies widely. Some plans cover older weight loss drugs like phentermine; others do not cover any weight loss medications at all.

If you have a Medicare Advantage plan (Part C), that plan sets its own rules for weight loss drug coverage. Some Advantage plans follow Medicare Part B guidelines; others have different policies. You will need to check your plan's formulary or call the plan directly to find out what is covered.

Key Takeaways

  • Medicare Part B covers semaglutide and tirzepatide only when prescribed for type 2 diabetes or heart disease, not for weight loss as a standalone goal.
  • Part D coverage of weight loss drugs varies by plan, so you must check your specific plan's formulary to know what you will pay.
  • Medicare Advantage plans set their own coverage rules and may differ from Original Medicare.
  • Even when Medicare covers a weight loss drug, you typically pay a copay or coinsurance amount at the pharmacy.
  • Your doctor must document a may have access to medical condition (diabetes or heart disease) for Part B coverage to explore.

How Medicare Part B covers weight loss drugs for diabetes and heart disease

When you have type 2 diabetes or heart disease and your doctor prescribes semaglutide or tirzepatide, Medicare Part B treats these as medications for those conditions, not as weight loss treatments. Your doctor must document in your medical record that the drug is being used to manage your diabetes or reduce your heart disease risk. The prescription itself does not need to say "for weight loss" — the diagnosis code your doctor uses determines how Medicare processes the claim.

Once Medicare Part B covers the drug, you pay 20 percent of the Medicare-approved amount after you have met your Part B deductible for the year. The deductible amount changes each year. In 2024, the Part B deductible was $240, but this figure changes annually. After you reach that deductible, Medicare pays 80 percent and you pay 20 percent for the rest of the calendar year.

If you have a Medigap supplemental insurance policy, it may cover some or all of your 20 percent coinsurance, depending on which Medigap plan you hold. Check your Medigap policy documents or call your Medigap insurer to confirm what portion of the drug cost they will cover.

Medicare Part D and weight loss medications

Part D plans each maintain their own list of covered drugs. Some Part D plans include weight loss medications on their formulary; many do not. The drugs most likely to appear on a Part D formulary are older, less expensive options like phentermine (a stimulant appetite suppressant) and orlistat (a fat-absorption blocker available over the counter). Newer drugs like semaglutide and tirzepatide are less commonly covered by Part D, though some plans do include them.

To find out whether your Part D plan covers a specific weight loss drug, log into your plan's website and search the formulary by drug name, or call the customer service number on your insurance card. When you call, ask whether the drug requires prior authorization — a step where your doctor must submit paperwork to the plan before the pharmacy will fill the prescription. Some plans require prior authorization for weight loss drugs even when they are on the formulary.

Part D plans also use cost-sharing tiers. A drug might be on the formulary but placed on a higher tier, meaning you pay more out of pocket. Tier 1 drugs (generics) cost the least; Tier 5 drugs (usually brand-name, non-preferred options) cost the most. Ask your plan which tier your weight loss drug is on so you know what to expect at the pharmacy.

Medicare Advantage plans and weight loss drug coverage

Medicare Advantage (Part C) plans are required to cover everything Original Medicare covers, including Part B coverage of semaglutide and tirzepatide for diabetes and heart disease. However, Advantage plans may add their own restrictions, such as requiring prior authorization or limiting how many doses you can receive per year.

Many Advantage plans also include Part D prescription drug coverage built into the plan. This means weight loss drugs may be covered under the Advantage plan's drug formulary rather than under Part B. Coverage rules and cost-sharing amounts differ from plan to plan. Some Advantage plans cover a broader range of weight loss medications than Original Medicare does; others cover fewer.

To understand your Advantage plan's coverage, review the plan's formulary (available on the plan's website) or call the plan's customer service line. Ask specifically whether weight loss drugs are covered, whether prior authorization is required, and what your out-of-pocket cost will be.

What happens if Medicare does not cover the weight loss drug your doctor prescribes

If your doctor prescribes a weight loss drug that Medicare does not cover, or if you do not have a may have access to condition like diabetes or heart disease, you have several options. You can pay the full cost out of pocket at the pharmacy. Prices vary widely depending on the drug and the pharmacy; semaglutide and tirzepatide typically cost several hundred dollars per month without insurance.

Some pharmaceutical manufacturers offer patient information programs that reduce or eliminate the cost of their drugs for people who meet income requirements. GLP-1 drugs like semaglutide and tirzepatide often have manufacturer programs. Contact the drug manufacturer directly or ask your doctor's office to help you find and explore for these programs.

You can also ask your doctor whether a different weight loss medication might be covered by your Medicare plan. Older drugs like phentermine are less expensive and more likely to be covered by Part D plans. Your doctor can help you weigh the benefits and drawbacks of different options based on your health.

How to check your coverage before filling a prescription

Before your doctor writes a prescription, ask whether the weight loss drug is covered by your Medicare plan. If you have Original Medicare with Part D, contact your Part D plan and ask them to check the formulary for you. If you have a Medicare Advantage plan, call that plan's customer service number. Have your plan member ID ready when you call.

When you speak to the plan, provide the drug name and strength (for example, "semaglutide 1 mg"). Ask whether it is on the formulary, what tier it is on, whether prior authorization is required, and what your copay or coinsurance will be. Ask also whether the plan has any quantity limits — some plans limit how many doses you can receive per month or per year.

If your doctor has not yet written the prescription, ask your doctor's office to contact your Medicare plan before writing it. Many doctor's offices have staff who handle insurance verification and can save you time and confusion. If the drug is not covered, your doctor can discuss alternatives with you.

Prior authorization and other plan requirements

Many Medicare plans require prior authorization before covering a weight loss drug. This means your doctor must submit paperwork to the plan explaining why the drug is medically necessary. For weight loss drugs, the plan may ask for documentation of your weight, your body mass index (BMI), previous weight loss attempts, and any related health conditions like diabetes or heart disease.

Prior authorization can take several days to several weeks. During this time, you cannot fill the prescription. To speed up the process, ask your doctor's office to submit the authorization request as soon as possible. Some plans have expedited review for urgent cases, though weight loss drugs are rarely considered urgent.

Some plans also impose quantity limits, meaning they will only cover a certain number of doses per month or per year. If your doctor prescribes a higher dose or more frequent injections than your plan allows, you may need to pay the difference out of pocket or work with your doctor to adjust the prescription to match your plan's limits.

Frequently Asked Questions

Does Medicare cover Ozempic or Mounjaro for weight loss?

Medicare Part B covers semaglutide (Ozempic) and tirzepatide (Mounjaro) only when prescribed for type 2 diabetes or heart disease, not for weight loss alone. If you have one of these conditions and your doctor prescribes the drug for that condition, Medicare Part B covers 80 percent after your deductible. Part D coverage varies by plan.

What if I have a Medicare Advantage plan instead of Original Medicare?

Medicare Advantage plans must cover what Original Medicare covers, but they may add their own rules like prior authorization or quantity limits. Check your Advantage plan's formulary or call the plan to learn what weight loss drugs are covered and what you will pay.

Can I appeal if my Medicare plan denies coverage for a weight loss drug?

Yes. If your plan denies coverage, your doctor can file an appeal on your behalf. The appeal process varies by plan, but you have the right to request a review. Contact your plan's customer service to ask how to file an appeal and what documentation your doctor should submit.

Will my copay be the same every month for a weight loss drug?

Your copay or coinsurance amount stays the same throughout the year, but it may change from year to year when your plan's formulary is updated. Some plans also have an annual out-of-pocket maximum; once you reach it, Medicare covers 100 percent of your drug costs for the rest of the year.

What should I do if the weight loss drug my doctor wants to prescribe is too expensive?

Ask your doctor about alternative weight loss medications that your plan covers. Ask also whether the drug manufacturer offers a patient information program. If cost remains a barrier, discuss with your doctor whether a lower dose or less frequent dosing schedule might work for your situation.