What Medicare covers for weight loss medications

Medicare Part D (prescription drug coverage) covers some weight loss drugs, but not all of them, and coverage rules vary by plan. The drugs Medicare is most likely to cover are older medications like phentermine and diethylpropion, which have been used for decades. Newer drugs like semaglutide (Ozempic, Wegovy) and tirzepatide (Zepbound, Mounjaro) have more restrictive coverage — many plans cover them only if you meet specific medical criteria, and some plans do not cover them at all.

Whether your plan covers a particular drug depends on which Part D plan you chose during open enrollment. Each plan maintains its own formulary — the official list of drugs it will pay for. A drug on one plan's formulary may not be on another's, even though both are Medicare plans. You need to check your specific plan's formulary, not just ask whether Medicare covers weight loss drugs in general.

Original Medicare (Parts A and B) does not cover weight loss drugs at all. If you are on Original Medicare and want prescription coverage, you must have a Part D plan. If you are in a Medicare Advantage plan (Part C), that plan includes drug coverage, and you check its formulary the same way.

Key Takeaways

  • Medicare Part D covers some weight loss drugs but not others, and coverage depends entirely on which specific plan you chose.
  • Newer drugs like semaglutide and tirzepatide have stricter limits — many plans require proof of diabetes, heart disease, or a BMI above a certain threshold before they will pay.
  • You find out what your plan covers by looking up your plan's formulary on Medicare.gov or calling the plan directly; asking your doctor is not enough.
  • If your plan does not cover the drug your doctor recommends, you can switch to a different Part D plan during the annual open enrollment period (October 15 to December 7).
  • Some plans charge a higher copay for weight loss drugs than for other prescriptions, and the copay amount varies by plan.

How to check what your Part D plan covers

Start by going to Medicare.gov and using the Plan Finder tool. You will need your Medicare number. Enter the drug name (the brand name or generic name both work), and the tool will show you which plans in your area cover it and what you would pay out of pocket.

If you already know which plan you are in, you can also call the plan directly — the phone number is on your insurance card. Tell them the drug name and ask whether it is on their formulary. Ask specifically whether there are restrictions, such as prior authorization (meaning your doctor has to get approval first) or step therapy (meaning you have to try a cheaper drug first and fail before they will pay for this one).

Your doctor's office may also check this for you, but do not rely on them to know all the details. Formularies change, and office staff do not always have the most current information. Checking yourself on Medicare.gov takes five minutes and is more reliable.

Prior authorization and step therapy requirements

Many Medicare plans that do cover newer weight loss drugs require prior authorization. This means your doctor has to submit paperwork to the plan showing that you meet the plan's medical criteria before the plan will agree to pay. Common criteria include a BMI of 30 or higher, or a BMI of 27 or higher plus a weight-related condition like type 2 diabetes or high blood pressure.

Some plans also use step therapy, which means they will only pay for the newer drug if you have already tried and failed on an older, cheaper drug first. For example, a plan might require you to try phentermine for a set period before they will cover semaglutide. Your doctor can request an exception if there is a medical reason you cannot take the first-line drug, but this adds time to the process.

Prior authorization typically takes one to two weeks. Step therapy can add several months. If your doctor prescribes a drug and the plan denies it, you have the right to appeal, but appeals also take time. Plan ahead with your doctor if you know you will need a weight loss drug.

Cost and copay amounts

If your plan covers a weight loss drug, you pay a copay at the pharmacy each time you fill the prescription. The copay amount depends on your plan and which tier the drug is on. Medicare plans typically have three to five tiers, with tier 1 being the cheapest (usually generic drugs) and higher tiers being more expensive.

Weight loss drugs are usually on a higher tier, so your copay might be $35 to $75 per prescription, or sometimes more. Some plans charge a percentage of the drug's cost (called coinsurance) instead of a flat copay. Once you reach your plan's out-of-pocket maximum for the year, the plan pays 100 percent of your drug costs for the rest of that calendar year.

If the copay is too high, ask your doctor whether the drug manufacturer offers a coupon or patient information program. Many do, though some programs do not work with Medicare. Your pharmacist can also tell you whether a generic version is available, which is usually cheaper.

Switching plans if your drug is not covered

If your current Part D plan does not cover the drug your doctor recommends, you can switch to a different plan. The annual open enrollment period runs from October 15 to December 7 each year. During this window, you can drop your current plan and join a new one, effective January 1.

Use the Plan Finder tool on Medicare.gov to see which plans in your area cover the drug you need and what the copay would be. Compare not just the drug coverage but also the plan's premiums and coverage for your other medications, since switching plans affects all your prescriptions.

If you miss the open enrollment window, you can only switch plans if you have a may have access to life event, such as moving to a new state or losing other insurance. Weight loss drug coverage alone is not a may have access to event, so plan ahead during open enrollment if this matters to you.

Original Medicare and weight loss drugs

If you are on Original Medicare (Parts A and B only, with no Part D plan), Medicare does not cover weight loss drugs at all. You would have to pay the full pharmacy price out of pocket, which can be hundreds of dollars per month for newer drugs.

You can add a Part D plan at any time, but if you do not sign up during your initial enrollment window (when you first turn 65 or first become may be able to access for Medicare), you may pay a late enrollment penalty for as long as you have Part D coverage. The penalty is about 1 percent of the national average Part D premium per month you were late, which adds up over time.

If you are considering adding Part D specifically for weight loss drug coverage, compare the monthly premium of the cheapest Part D plan in your area against the out-of-pocket cost of paying for the drug without insurance. Sometimes paying out of pocket is cheaper, especially if you only need the drug for a few months.

Medicare Advantage and weight loss drugs

Medicare Advantage plans (Part C) include prescription drug coverage as part of the plan. Coverage for weight loss drugs works the same way as in standalone Part D plans — each Advantage plan has its own formulary, and coverage varies. Some Advantage plans cover newer weight loss drugs with few restrictions, while others do not cover them at all.

If you are in an Advantage plan and want to switch to a plan with better weight loss drug coverage, you can do so during the annual open enrollment period. You can also switch from an Advantage plan back to Original Medicare plus a Part D plan, though this is a one-way change — if you switch back to Original Medicare, you cannot return to Advantage until the next open enrollment period.

Frequently Asked Questions

Does Medicare cover Ozempic or Wegovy for weight loss?

Some Medicare plans cover semaglutide (Ozempic, Wegovy), but not all. Coverage depends on your specific plan's formulary and usually requires prior authorization and proof that you have a may have access to condition like type 2 diabetes or a BMI above a certain threshold. Check your plan's formulary on Medicare.gov or call your plan to find out.

What if my doctor says I need a weight loss drug but my plan will not cover it?

You can ask your doctor to request an exception from the plan, explaining why the drug is medically necessary for you. The plan has 72 hours to respond. If they deny the exception, you can appeal. You can also switch to a different Part D plan during open enrollment (October 15 to December 7) if another plan covers the drug.

Will I have to pay a penalty if I do not sign up for Part D when I turn 65?

If you do not have prescription drug coverage when you first become may be able to access and you later sign up for Part D, you will pay a late enrollment penalty for as long as you have Part D coverage. The penalty is roughly 1 percent of the national average Part D premium per month you were late. If you do not think you need prescriptions now, you can wait, but the penalty applies if you change your mind later.

Can I use a manufacturer coupon for a weight loss drug if Medicare covers it?

It depends on the plan and the coupon. Some manufacturer coupons work with Medicare, but others do not. Ask your pharmacist or the drug manufacturer before you try to use a coupon. If the coupon does not work with Medicare, paying the plan's copay is usually your only option.

What happens to my weight loss drug coverage if I switch from Original Medicare to a Medicare Advantage plan?

Coverage depends on which Advantage plan you choose. Each plan has its own formulary. Some Advantage plans cover weight loss drugs with fewer restrictions than Part D plans, and some cover them more restrictively. Check the formulary of any Advantage plan you are considering before you switch.