Medicare Part D covers Mounjaro, but your out-of-pocket cost depends on your plan and which tier the drug sits on

Mounjaro (tirzepatide) is a newer injectable medication for type 2 diabetes. Medicare Part D — the prescription drug coverage part of Medicare — does cover it, but not all Part D plans include it, and the ones that do may charge different copays or coinsurance amounts. Your actual cost will depend on which specific plan you have, what tier Mounjaro is on within that plan, and how much you have already spent on drugs this year.

The drug is not covered by Original Medicare (Part A and Part B). If you have Original Medicare and want Mounjaro, you need a Part D plan, a Medicare Advantage plan with drug coverage (Part C), or you pay the full price out of pocket. Mounjaro is not inexpensive — the retail price is around $1,000 per month before any coverage — so understanding your coverage options matters.

Key Takeaways

  • Mounjaro is covered by most Medicare Part D plans, but you must check your specific plan's formulary to see which tier it is on and what your copay or coinsurance will be.
  • Medicare Advantage plans (Part C) with drug coverage also cover Mounjaro in most cases, though coverage rules and costs vary by plan.
  • Original Medicare does not cover Mounjaro, so you need Part D or a Medicare Advantage plan with drug benefits.
  • Manufacturer copay information programs can lower your out-of-pocket cost to as little as $25 per month if you meet income requirements.
  • Your costs change depending on which phase of the Part D benefit year you are in — deductible, initial coverage, coverage gap, or catastrophic coverage.

How Part D coverage works for Mounjaro

Part D plans organize drugs into tiers, usually four or five levels. Mounjaro is typically placed on Tier 3 or Tier 4 (the higher tiers), which means your copay or coinsurance is higher than for generic or older drugs. A Tier 3 copay might be $50 to $75 per injection; a Tier 4 copay could be $100 or more. Some plans use coinsurance instead, meaning you pay a percentage of the drug's cost — often 25% to 33% — rather than a flat copay.

Before your Part D plan pays anything, you must meet your annual deductible. Most Part D plans have a deductible between $500 and $550, though some plans have no deductible. Once you meet the deductible, you enter the initial coverage phase, where the plan and you share the cost. After you and your plan together spend a certain amount (around $5,850 in 2024, though this changes yearly), you enter the coverage gap — sometimes called the "donut hole" — where you pay a larger share of the cost. Once your total out-of-pocket spending reaches a certain threshold (around $7,050 in 2024), you enter catastrophic coverage, where Medicare pays most of the cost.

The exact amounts and phases change each year, so check your plan's summary of benefits or call the plan directly to understand where Mounjaro falls in your specific coverage.

Medicare Advantage plans and Mounjaro coverage

If you have a Medicare Advantage plan (Part C) that includes drug coverage, Mounjaro is usually covered, but the rules differ from Part D. Medicare Advantage plans set their own formularies and cost-sharing amounts. Some plans may require prior authorization — meaning your doctor must get approval from the plan before you start the drug. Others may require you to try a different diabetes medication first before they will cover Mounjaro.

Call your Medicare Advantage plan's customer service number (on your insurance card) and ask directly: Is Mounjaro on your formulary? What tier is it on? Do you require prior authorization? What is the copay or coinsurance? These answers will tell you what to expect.

Copay information programs that can lower your cost

Eli Lilly, the manufacturer of Mounjaro, runs a copay information program called the Mounjaro Savings Program. If you have Part D or commercial insurance, you may be able to pay as little as $25 per injection, regardless of your plan's copay. To use this program, you must have a valid prescription, be a U.S. resident, and meet income limits. The income threshold is typically around 400% of the federal poverty line, which for a single person in 2024 is roughly $56,000 per year.

You do not explore for this program through Medicare. Instead, you work with your pharmacy or doctor's office. When you fill your prescription, tell the pharmacy you want to use the Mounjaro Savings Program. The pharmacy can help you enroll, or you can visit the program's website directly. The copay card is sent to you, and you use it at the pharmacy each time you fill your prescription.

If your income is below 200% of the federal poverty line (roughly $28,000 for a single person), you may also be able to get Mounjaro for free through the program, depending on your insurance type.

What to do if your plan does not cover Mounjaro

If your Part D plan does not include Mounjaro on its formulary, you have options. First, ask your doctor to request a formulary exception. This is a formal request to the plan asking them to cover a drug that is not normally on their list. Plans must consider these requests, and they often approve them if your doctor explains why Mounjaro is medically necessary for you. The process usually takes a few business days to a week.

Second, you can switch to a different Part D plan during the annual enrollment period (October 15 to December 7 each year) or if you may have access to for a special enrollment period. Many Part D plans do cover Mounjaro, so shopping around may find you a plan with better coverage and a lower copay. Use the Medicare Plan Finder tool on Medicare.gov to compare plans in your area and see which ones include Mounjaro and at what cost.

Third, if you cannot get coverage and cannot afford the copay information program, talk to your doctor about other diabetes medications that may be covered at a lower cost. GLP-1 drugs like Ozempic or Victoza, and older insulin medications, are often covered with lower copays.

How to check your specific plan's coverage

The fastest way to know what you will pay is to check your plan's formulary — the official list of covered drugs. You can find this on your plan's website or by calling the customer service number on your insurance card. Have your prescription ready when you call, because the representative will need to know the exact dose and frequency your doctor prescribed.

You can also use the Medicare Plan Finder at Medicare.gov. Enter Mounjaro and your zip code, and it will show you which plans in your area cover it and what the estimated cost is. This tool is especially useful if you are shopping for a new plan during open enrollment.

If you are enrolled in Original Medicare and do not have Part D, you can still add a Part D plan during the annual enrollment period or if you have a may have access to life event (like losing other drug coverage). There is no penalty for adding Part D late if you have had creditable coverage from another source, but if you go without Part D coverage for more than 63 days after you become may be able to access, you may face a permanent penalty when you do enroll.

Frequently Asked Questions

Will Medicare cover Mounjaro if my doctor says I need it for weight loss instead of diabetes?

No. Medicare Part D covers Mounjaro only for type 2 diabetes treatment. If your doctor prescribes it for weight loss alone, Medicare will not cover it. Some commercial insurance plans may cover it for weight loss, but Medicare does not. You would need to pay out of pocket or explore other weight loss options covered by Medicare.

What happens to my Mounjaro coverage if I switch from Part D to a Medicare Advantage plan?

Coverage depends on your new Medicare Advantage plan's formulary. Most Medicare Advantage plans with drug coverage do include Mounjaro, but the copay and prior authorization rules may be different. Before you switch, check the new plan's formulary to confirm Mounjaro is covered and understand the cost.

Can I use the Mounjaro Savings Program if I am on Medicare?

Yes, if you have Part D or a Medicare Advantage plan with drug coverage. The savings program works alongside your insurance. You still use your insurance, but the copay card reduces what you pay out of pocket. If you have Original Medicare without Part D, the savings program does not explore because Original Medicare does not cover Mounjaro at all.

Does Medicare cover the cost of doctor visits to start Mounjaro?

Yes. Medicare Part B covers office visits with your doctor, including the visit where you start a new medication. You pay your Part B copay or coinsurance for the visit itself. The drug cost is separate and covered by Part D or your Medicare Advantage plan.

What if I cannot afford Mounjaro even with copay information?

Talk to your doctor about other diabetes medications that may have lower copays under your plan. Older GLP-1 drugs, SGLT2 inhibitors, and metformin are often covered at lower costs. You can also ask your doctor's office about patient information programs run by other manufacturers, or contact your state's pharmaceutical information program, which may help low-income seniors pay for medications.