Medicare's Current Position on Weight Loss Medications

Medicare Part D covers some weight loss drugs, but not all of them, and the rules depend on which drug you take and why your doctor prescribed it. As of now, Medicare covers semaglutide (Ozempic, Wegovy) and tirzepatide (Zepbound, Mounjaro) for weight loss in certain circumstances, but coverage is not automatic and varies by your specific Part D plan. Other weight loss drugs like phentermine and naltrexone-bupropion may be covered by some plans but not others.

The key difference is that Medicare will cover these drugs when prescribed for type 2 diabetes or obesity-related conditions, but the exact terms — what you pay, whether you need prior approval, whether there are quantity limits — depend on your individual plan's formulary. A formulary is the list of drugs your plan covers. You need to check your own plan's formulary to know whether a specific drug is covered and what your out-of-pocket cost will be.

Key Takeaways

  • Medicare Part D covers semaglutide and tirzepatide for weight loss, but coverage rules and costs vary by plan and by the reason your doctor prescribes the drug.
  • You must check your specific Part D plan's formulary to see whether a weight loss drug is covered and what tier (cost level) it falls on.
  • Many plans require prior authorization before the pharmacy will fill a weight loss drug prescription, meaning your doctor must get approval first.
  • If your plan does not cover a drug your doctor wants to prescribe, you can request an exception, ask your doctor to appeal, or switch plans during the annual open enrollment period.

How Medicare Part D Decides What Weight Loss Drugs to Cover

Each Part D plan is run by a private insurance company and creates its own formulary — the official list of covered drugs. The plan decides which weight loss drugs to include, at what cost tier, and under what conditions. This means two people on different Part D plans may have completely different coverage for the same drug.

Plans typically place drugs on tiers: Tier 1 (generic, lowest cost), Tier 2 (preferred brand), Tier 3 (non-preferred brand), Tier 4 (specialty), or Tier 5 (highest cost). A weight loss drug might be on Tier 2 in one plan and Tier 4 in another, which means your copay or coinsurance could be $15 or $150 for the same medication. Plans also set annual limits on how many doses or refills you can receive, and many require prior authorization — your doctor must prove medical necessity before the pharmacy will fill the prescription.

What You Pay Out of Pocket

Your out-of-pocket cost for a weight loss drug covered by Medicare Part D depends on which tier the drug is on in your plan and where you are in the coverage year. In 2024, you pay a copay or coinsurance for each prescription until you reach your plan's deductible and then your initial coverage limit. Once you hit the coverage gap (sometimes called the "donut hole"), your costs rise sharply until you reach catastrophic coverage, where Medicare pays most of the cost.

For a specialty drug like semaglutide or tirzepatide, you might pay 25% to 33% coinsurance rather than a flat copay, which can mean $200 to $400 per month depending on the dose and your plan. Some plans waive the deductible for certain drugs, and some offer copay information programs. The only way to know your actual cost is to log into your plan's website, search for the specific drug and dose, and see what your plan shows.

When Your Doctor Needs Prior Authorization

Most Medicare Part D plans require prior authorization before they will cover a weight loss drug. This means your doctor's office must submit a request to the insurance company, usually including your diagnosis, your weight, your BMI, and proof that you have tried other treatments or that the drug is medically necessary. The plan then approves or denies the request, usually within 24 to 72 hours.

If the plan denies prior authorization, your doctor can appeal the decision or request an exception. An exception is a formal request to cover a drug that is not on the formulary or to waive a quantity limit. The appeals and exceptions process can take one to two weeks. During this time, you can ask your pharmacy to hold the prescription or pay out of pocket if you cannot wait. Some manufacturers offer copay cards or patient information programs that reduce your cost while the appeal is pending.

What to Do If Your Plan Does Not Cover the Drug Your Doctor Wants

If your Part D plan's formulary does not include the weight loss drug your doctor prescribed, you have three main options. First, ask your doctor to request a formulary exception — a formal appeal to the plan asking them to cover the drug anyway. Plans must respond to exceptions within 72 hours for urgent requests and within 7 calendar days for standard requests. Your doctor will need to explain why this specific drug is medically necessary for you.

Second, ask your doctor whether an alternative weight loss drug on your plan's formulary would work for you. Your plan may cover a different drug in the same class, or your doctor may be willing to prescribe a different medication. Third, if you are unhappy with your plan's coverage, you can switch to a different Part D plan during the annual open enrollment period, which runs from October 15 to December 7 each year. You can compare plans on Medicare.gov and choose one that covers the drug you need.

How to Check Your Plan's Coverage Right Now

To find out whether your specific Part D plan covers a weight loss drug, start by logging into your plan's website or calling the customer service number on your insurance card. Ask to speak with someone in the pharmacy benefits department. Have the drug name, dose, and quantity ready — for example, "semaglutide 1 mg pen, one pen per week."

The plan representative can tell you whether the drug is on the formulary, what tier it is on, what your copay or coinsurance will be, whether prior authorization is required, and whether there are quantity limits. You can also use the Medicare Plan Finder tool on Medicare.gov to compare Part D plans and see which ones cover specific drugs, though the tool does not show exact copay amounts — you have to contact the plan for that. Write down the answers and ask for a confirmation number or reference number in case you need to follow up.

Changes Coming to Medicare Coverage of Weight Loss Drugs

Medicare rules and formularies change every year. Starting in 2025, some plans may expand coverage of weight loss drugs or move them to lower cost tiers as these medications become more widely prescribed and as manufacturers negotiate prices with Medicare. However, coverage is not may provide to improve — some plans may add quantity limits or require step therapy (trying a cheaper drug first) before covering a weight loss drug.

The Centers for Medicare & Medicaid Services (CMS) does not set a single national rule for weight loss drug coverage; instead, each Part D plan makes its own decisions within federal guidelines. This means you should check your plan's formulary every year during open enrollment, even if you were covered last year. Formularies change on January 1 each year, and a drug that was covered in 2024 might not be covered in 2025 under your current plan.

Frequently Asked Questions

Does Medicare Part B cover weight loss drugs?

No. Medicare Part B covers doctor visits, lab work, and some medical equipment, but not prescription drugs. Weight loss drugs are covered only through Medicare Part D (prescription drug coverage). If you do not have Part D, you can enroll during the annual open enrollment period or during a special enrollment period if you lose coverage.

What if I cannot afford the copay for a weight loss drug?

Ask your doctor's office whether the drug manufacturer offers a copay information card or patient information program — many do, and they can reduce your out-of-pocket cost to $0 or a small flat fee. You can also ask your plan whether it has a copay information program. If you have limited income, you may be may be able to access for Extra Help (also called the Low-Income Subsidy), which reduces your Part D costs; you can explore through Social Security.

Can I use GLP-1 drugs like Ozempic or Wegovy if I have Medicare?

Yes, if your Part D plan covers them. Ozempic is FDA-approved for type 2 diabetes and is usually covered when prescribed for that reason. Wegovy is the same drug (semaglutide) but is FDA-approved specifically for weight loss and chronic weight management. Coverage depends on your plan's formulary and whether your doctor can document medical necessity. Check your plan's website or call customer service to confirm.

What happens if I switch Part D plans mid-year?

You cannot switch Part D plans in the middle of the year unless you have a may have access to life event — such as losing your current coverage, moving out of your plan's service area, or becoming may be able to access for Extra Help. If you do not have a may have access to event, you must wait until the annual open enrollment period (October 15 to December 7) to switch plans. Your new coverage starts on January 1.

Do I need to be obese to get Medicare coverage of weight loss drugs?

Not necessarily. Medicare Part D plans cover weight loss drugs when a doctor prescribes them for a medically necessary reason, which may include type 2 diabetes, heart disease, or obesity-related conditions. The exact medical criteria depend on your plan's formulary and the drug. Your doctor will need to document the medical reason in your chart, and the plan may require prior authorization to confirm it meets their coverage rules.