What Medicare Covers for Mounjaro

Medicare Part D (prescription drug coverage) covers Mounjaro, but whether you pay nothing, a copay, or a percentage depends on which Part D plan you chose and whether your doctor's dosage matches the plan's rules. Mounjaro is a brand-name injectable medication for type 2 diabetes made by Eli Lilly. Most Part D plans place it on their formulary — the list of covered drugs — but usually in a higher tier, which means higher out-of-pocket costs than generic alternatives.

Original Medicare (Part A and B) does not cover Mounjaro on its own. You need Part D coverage, or you need to be in a Medicare Advantage plan (Part C) that includes drug coverage. If you have neither, you pay the full retail price, which runs between $900 and $1,300 per month before any manufacturer discounts.

The actual amount you pay depends on three things: your plan's formulary tier for Mounjaro, your deductible status, and whether you have reached the coverage gap (the "donut hole"). Some plans require prior authorization — your doctor must submit paperwork proving you have tried other medications first — before the plan will pay.

Key Takeaways

  • Medicare Part D covers Mounjaro on most plans, but usually places it in a higher cost tier, meaning you pay more than you would for older diabetes drugs.
  • Your actual out-of-pocket cost depends on your specific plan's formulary, your deductible, and whether your plan requires prior authorization from your doctor.
  • Original Medicare alone does not cover Mounjaro; you must have Part D or a Medicare Advantage plan with drug coverage.
  • If your plan does not cover Mounjaro, Eli Lilly offers a copay card that can reduce your cost to as low as $25 per month, but only if you have commercial insurance or Part D coverage.

How to Check Your Plan's Coverage Before You Fill a Prescription

Call your Part D plan's customer service number — it is on the back of your insurance card — and ask three specific questions: Is Mounjaro on your formulary? What tier is it in? Does your plan require prior authorization? Write down the answers and the date you called, because coverage can change and you may need proof later.

You can also check online through your plan's website. Most plans have a drug search tool where you type "Mounjaro" and it shows the tier, copay or coinsurance amount, and any restrictions. If you cannot find it online or the website is unclear, the phone call is faster and more reliable.

If your plan does not cover Mounjaro at all, you have options: switch to a different Part D plan during the annual enrollment period (October 15 to December 7), ask your doctor whether a different diabetes medication on your plan's formulary might work for you, or look into the Eli Lilly copay card, which some plans allow.

Prior Authorization and Step Therapy Requirements

Many Medicare Part D plans require prior authorization before they will pay for Mounjaro. This means your doctor must submit a form to the plan proving that you have already tried metformin, a sulfonylurea, or another older diabetes drug and it did not work well enough or caused side effects. The plan then decides whether to approve Mounjaro or ask you to try something else first.

This process usually takes three to five business days, but can take longer if the plan asks for more information from your doctor. Your doctor's office handles the paperwork, not you, but you should call your doctor's office to confirm they have submitted it and to ask when you can expect an answer. Do not wait for the authorization to come through before calling the pharmacy — tell the pharmacy you are waiting for prior authorization so they know not to charge you yet.

If the plan denies authorization, you have the right to appeal. Your doctor can submit additional medical records or a letter explaining why Mounjaro is medically necessary for you. The appeal process takes longer — usually 7 to 14 days — but many denials are overturned on appeal.

What You Pay at the Pharmacy

Once your plan approves Mounjaro, what you pay depends on where you are in your plan's benefit year. If you have not yet met your deductible, you pay the full price until you do. Once you meet the deductible, you pay a copay (a fixed dollar amount per prescription) or coinsurance (a percentage of the drug's cost). For Mounjaro, copays typically range from $50 to $250 per month on plans that use copays, and coinsurance is usually 25% to 33% of the cost.

After you and your plan together spend a certain amount on drugs — usually $5,030 in 2024, though this changes yearly — you enter the coverage gap. In the gap, you pay a higher percentage of the cost. Once your out-of-pocket spending reaches a second limit (usually around $8,000), catastrophic coverage kicks in and your plan pays most of the cost.

Mounjaro comes in a prefilled pen with four doses per month. You inject it once a week. Your pharmacy will dispense it as a 30-day supply, and you will pay your copay or coinsurance once per month.

Using the Eli Lilly Copay Card if Your Plan Covers Mounjaro

Eli Lilly offers a copay card that can reduce your monthly cost to $25 if you have Medicare Part D or commercial insurance. You do not need to be uninsured to use it. The card works by having Eli Lilly pay the difference between your plan's copay and $25, up to a limit of $250 per month.

To use the card, you read it from Mounjaro's official website or ask your doctor's office for a printed version. You present it to the pharmacy when you fill your prescription. The pharmacy scans it and applies the discount at the register. You still need your insurance card — the copay card works alongside your Part D coverage, not instead of it.

The copay card has an annual maximum. Once you reach it, you pay your plan's normal copay for the rest of the year. Eli Lilly's website shows the current maximum and tracks how much you have used. If you reach the maximum before the year ends, your doctor can discuss whether a different medication might be more affordable for you for the remainder of the year.

What to Do if Your Plan Denies Coverage

If your Part D plan denies Mounjaro outright or after prior authorization, you have three paths forward. First, you can appeal the denial. Ask your doctor to submit a letter explaining why Mounjaro is medically necessary — for example, if you have tried other drugs and they did not work, or if you have a condition that makes other drugs unsafe. Appeals often succeed, especially if your doctor provides strong medical justification.

Second, you can switch plans. If you are in a Part D standalone plan, you can switch to a different Part D plan during the annual enrollment period. If you are in a Medicare Advantage plan, you can switch to Original Medicare plus a different Part D plan, or to a different Medicare Advantage plan. The enrollment period runs from October 15 to December 7 each year, and the new coverage starts January 1.

Third, you can pay out of pocket and use the Eli Lilly copay card. If you have commercial insurance or Part D coverage (even if the plan does not cover Mounjaro), the copay card can reduce your cost to $25 per month. This is not ideal, but it is an option if you cannot get coverage approved and cannot switch plans.

Frequently Asked Questions

Does Medicare Part B cover Mounjaro injections at a doctor's office?

No. Part B covers injectable drugs only if they are administered in a doctor's office or hospital setting. Mounjaro is a self-injected drug you use at home, so Part B does not cover it. You need Part D or a Medicare Advantage plan with drug coverage.

Will my copay for Mounjaro stay the same all year?

It may change once you enter the coverage gap. Before the gap, you pay your plan's standard copay or coinsurance. In the gap, you pay a higher percentage. Once you reach catastrophic coverage, your plan pays most of the cost and your copay drops. Check your plan's summary of benefits to see the exact amounts at each stage.

Can I use GoodRx or another discount card instead of my Medicare plan?

You cannot use GoodRx or similar discount cards if you have Medicare. Using a discount card instead of your insurance is considered "coordinating benefits" and is not allowed. You must use your Part D plan. However, you can use the Eli Lilly copay card on top of your Part D coverage.

What if I switch from a different diabetes drug to Mounjaro — will my plan cover both?

Your plan will cover Mounjaro once it is authorized, but you should stop taking the previous drug unless your doctor tells you otherwise. Taking two diabetes drugs at the same time is usually not necessary and can be unsafe. Talk to your doctor about the timing of the switch before you fill the Mounjaro prescription.

Does Medicare cover Mounjaro for weight loss if I do not have diabetes?

No. Medicare covers Mounjaro only for type 2 diabetes. If you want to use it for weight loss without diabetes, you would need commercial insurance or to pay out of pocket. Medicare does not cover weight-loss drugs except in very limited circumstances unrelated to Mounjaro.