Medicare covers three weight loss drugs, but only under specific conditions

Medicare Part D covers semaglutide (Ozempic, Wegovy), tirzepatide (Zepbound), and phentermine, but coverage depends on your plan and whether your doctor documents medical need. Not every Medicare plan covers all three, and some plans may require you to try other treatments first or pay a higher share of the cost. The drug itself must be prescribed for weight loss — using a diabetes version of semaglutide (like Januvia) does not automatically mean your weight loss use is covered.

Coverage also depends on your BMI and any weight-related health conditions you have. Most plans require a BMI of 30 or higher, or 27 or higher if you have diabetes, high blood pressure, or heart disease. Your doctor's notes must show the medical reason for the prescription, not just weight loss for appearance.

Key Takeaways

  • Medicare Part D covers semaglutide, tirzepatide, and phentermine, but your specific plan decides whether to include them and at what cost tier.
  • Your doctor must document that you have a weight-related health condition — such as type 2 diabetes, high blood pressure, or heart disease — for the prescription to be covered.
  • You will need to check your plan's formulary (the list of covered drugs) before your doctor prescribes, because coverage and out-of-pocket costs vary widely between plans.
  • Some plans require step therapy, meaning your doctor must show you tried diet, exercise, or other drugs first before the plan will pay for weight loss medications.
  • Costs range from a copay of $15 to $75 per month to no coverage at all, depending on your plan and the specific drug.

How to learn about your plan covers a specific weight loss drug

Start by finding your plan's formulary on Medicare.gov or your plan's website. Search for the drug name (semaglutide, tirzepatide, or phentermine) and note which tier it is on — Tier 1 drugs cost less, Tier 4 or 5 drugs cost more. The formulary also tells you whether the plan requires prior authorization (your doctor must get permission before you fill the prescription) or step therapy (you must try something else first).

If you cannot find the formulary online, call your plan's customer service number on the back of your Medicare card. Have the drug name and strength ready (for example, semaglutide 0.5 mg pen). Ask three things: Is it covered? What tier is it on? Does it need prior authorization? Write down the answers and the date you called.

If your current plan does not cover the drug your doctor wants to prescribe, you can switch to a different Part D plan during the annual open enrollment period (October 15 to December 7 each year). Some plans cover all three drugs; others cover only one or two. Comparing plans takes time, but it can save you hundreds of dollars per year.

What your doctor needs to document for coverage

Your doctor's prescription note must state that you have a medical reason for weight loss treatment. This is not optional — without it, the plan will deny the claim. The medical reason is usually one of these: type 2 diabetes, high blood pressure, heart disease, sleep apnea, or osteoarthritis made worse by weight.

Your doctor should also document your current BMI and weight-related symptoms. For example: "Patient has BMI of 32 and type 2 diabetes. Prescribing semaglutide to reduce cardiovascular risk." This language tells the plan the drug is medically necessary, not cosmetic.

If your doctor is unsure what to write, show them your plan's coverage rules. Many plans post these on their websites under "Prior Authorization Requirements" or "Coverage Policies." Your doctor can also call the plan's prior authorization line to ask what documentation is needed before writing the prescription.

Prior authorization and step therapy delays

Prior authorization means your doctor must submit the prescription to your plan for approval before you can fill it. This usually takes 3 to 5 business days but can take longer if the plan asks for more information. During this time, you cannot start the drug.

Step therapy is stricter. It means your plan will only cover the weight loss drug if you have already tried and failed diet and exercise, or tried another drug first (often phentermine before semaglutide). Your doctor must document the previous attempts in writing. If you have already tried these things, ask your doctor to include that history in the prior authorization request — it speeds approval.

If your plan denies coverage, you have the right to appeal. Your doctor can submit additional medical records or a letter explaining why the drug is necessary for your specific situation. Appeals often succeed, especially if your doctor provides new information the plan did not see the first time.

Out-of-pocket costs and how to lower them

Costs vary by plan and drug. Phentermine, a generic pill, often costs $15 to $30 per month on most plans. Semaglutide and tirzepatide are brand-name injectables and typically cost $50 to $75 per month in copays, though some plans charge more. A few plans do not cover these drugs at all.

If your copay is high, ask your doctor whether a generic alternative exists. Phentermine is generic and much cheaper than semaglutide or tirzepatide, though it works differently and is not suitable for everyone. Your doctor can tell you whether it is an option for your situation.

Some drug manufacturers offer copay cards that reduce your out-of-pocket cost. Novo Nordisk (which makes semaglutide) and Eli Lilly (which makes tirzepatide) both have programs for Medicare patients. Ask your doctor's office or pharmacist whether you may have access to. These cards can lower your copay to $0 to $25 per month, though they have income limits and other restrictions.

What happens if your plan does not cover the drug

If your plan denies coverage and an appeal fails, you have two options: pay out of pocket or switch plans. Paying out of pocket for semaglutide or tirzepatide costs $900 to $1,500 per month without insurance, which is not realistic for most people. Phentermine without insurance costs $30 to $100 per month, depending on the pharmacy.

Switching plans is usually the better choice. During the annual open enrollment period (October 15 to December 7), you can join a different Part D plan that covers the drug you need. Use the Medicare Plan Finder tool on Medicare.gov to compare plans in your area. Filter by the drug name and see which plans cover it and at what cost. You can switch once per year during open enrollment, or during a Special Enrollment Period if you have a may have access to life event (such as moving or losing other insurance).

If you need the drug urgently and your plan does not cover it, ask your doctor about phentermine as a temporary option. It is covered by most plans and costs less, though it is not the same as semaglutide or tirzepatide. Your doctor can discuss whether it is appropriate for your health situation.

Medicare Advantage plans and weight loss drugs

If you have a Medicare Advantage plan (Part C), coverage for weight loss drugs works differently. Medicare Advantage plans are run by private insurance companies and set their own rules. Some cover semaglutide and tirzepatide; others do not. Some require step therapy or prior authorization; others do not.

To find out what your Medicare Advantage plan covers, call the plan's customer service number on your insurance card. Ask the same three questions: Is it covered? What is the copay? Does it need prior authorization? Medicare Advantage plans often have lower copays than Part D plans, but they may have stricter step therapy requirements.

If your Medicare Advantage plan does not cover the drug you need, you can switch to Original Medicare plus a Part D plan during the annual open enrollment period. This gives you access to more Part D plans that may cover the drug. However, switching away from Medicare Advantage is permanent until the next open enrollment period, so think carefully before making the change.

Frequently Asked Questions

Does Medicare cover Ozempic for weight loss?

Medicare Part D covers semaglutide (Ozempic's generic name) when prescribed for weight loss, but only if your plan includes it on its formulary and your doctor documents a medical reason such as diabetes or heart disease. Ozempic is the brand name for diabetes use; Wegovy is the brand name for weight loss use. Medicare covers both, but your plan decides whether to include it and at what cost.

What if my doctor prescribes a weight loss drug but my plan says it is not covered?

Ask your doctor to submit a prior authorization request with detailed medical information about why you need the drug. If the plan still denies it, you can appeal. Your doctor can submit additional records or a letter explaining your health situation. Many appeals succeed. If the appeal fails, you can switch to a different Part D plan during open enrollment that does cover the drug.

Will Medicare cover weight loss drugs if I do not have diabetes or heart disease?

Most plans require a weight-related health condition for coverage. However, some plans cover weight loss drugs for BMI of 30 or higher alone, without requiring another condition. Check your plan's formulary or call customer service to ask. If your plan does not cover it, you can switch during open enrollment to one that does.

How much does semaglutide or tirzepatide cost with Medicare?

Copays typically range from $50 to $75 per month, depending on your plan and the drug tier. Some plans charge more; a few do not cover these drugs at all. Copay cards from the drug manufacturers can lower your cost to $0 to $25 per month if you meet income and other requirements. Call your doctor's office or pharmacist to ask about copay card programs.

Can I use a GoodRx coupon instead of my Medicare coverage?

You can, but it is usually not a good idea. Medicare rules say you cannot use both your Part D coverage and a discount coupon for the same prescription in the same month. If the coupon price is lower than your copay, you can use the coupon, but you will not earn progress toward your deductible or out-of-pocket maximum. Ask your pharmacist to show you both prices before you decide.