Does Medicare Cover Mounjaro?

The key distinction: diabetes vs. weight loss

Whether Medicare covers Mounjaro comes down to one thing: why it was prescribed. Mounjaro (the brand name for tirzepatide) is FDA-approved only to improve glycemic control — blood sugar — in adults with type 2 diabetes. It is NOT FDA-approved for weight loss. The very same active ingredient is sold under a different brand name, Zepbound, for chronic weight management.

This distinction matters because Medicare treats the two purposes very differently. When Mounjaro is prescribed for type 2 diabetes (its approved use), a Part D plan may cover it. When any drug is prescribed for weight loss, federal law blocks Medicare Part D from paying for it — more on that below.

How Part D covers Mounjaro for type 2 diabetes

Medicare prescription drug coverage comes through Part D — either a standalone Part D plan (a PDP) that you add to Original Medicare, or a Medicare Advantage plan that includes drug coverage (an MA-PD). These plans may cover Mounjaro when it is prescribed for type 2 diabetes.

Coverage is never automatic or universal, though. Whether your particular plan covers Mounjaro — and what you pay — depends on that plan's formulary (its list of covered drugs). Plans differ widely, so a drug covered on one plan may be excluded on another.

Two common requirements can also apply before a plan will pay:

• Prior authorization — your doctor must get the plan's approval first, often by confirming you have type 2 diabetes.
• Step therapy — the plan may require you to try one or more lower-cost diabetes drugs before it will cover Mounjaro.
• Original Medicare (Part A and Part B) does NOT cover Mounjaro — it is a self-administered outpatient drug, which Parts A and B do not pay for.

Why Medicare won't cover Mounjaro for weight loss

If your doctor prescribes Mounjaro to help you lose weight — an off-label use — Medicare Part D will not cover it. This is not a plan-by-plan choice; it is set by federal law. The statutory Part D exclusion specifically bars coverage of “agents when used for anorexia, weight loss, or weight gain.” CMS reads this to mean that any drug used for weight loss falls outside the definition of a covered Part D drug.

Medicare considered changing this. But in the CY2026 final rule announced in April 2025, CMS confirmed it would NOT finalize a proposal to reinterpret the exclusion and allow Part D coverage of anti-obesity medications. So through 2026, GLP-1 drugs remain non-covered for weight loss under standard Part D rules — and that includes Mounjaro used off-label for weight loss.

The GLP-1 Bridge and BALANCE Model — and why Mounjaro is left out

There are two new federal programs that expand access to weight-loss GLP-1s — but neither one covers Mounjaro.

The Medicare GLP-1 Bridge is a short-term demonstration that gives eligible Part D beneficiaries access to certain weight-loss GLP-1 drugs for a flat $50 per month copay, running from July 1, 2026 through December 31, 2027. The Bridge covers all formulations of Foundayo, all formulations of Wegovy, and the KwikPen formulation of Zepbound. Mounjaro is specifically NOT included — because it is not approved for weight loss.

One caution about the Bridge: that $50 monthly copay does NOT count toward your Part D deductible, and it does NOT count toward the $2,100 annual out-of-pocket cap on Part D drug costs.

The broader BALANCE Model (Better Approaches to Lifestyle and Nutrition for Comprehensive hEalth) is a separate, voluntary CMS Innovation Center test. It lets participating Part D plans and state Medicaid agencies cover GLP-1s for weight management along with lifestyle support. It is a demonstration, not part of the standard Part D benefit, so availability depends on whether your plan or state chooses to take part. Like the Bridge, it is geared toward weight-management drugs, not Mounjaro's diabetes indication.

What Mounjaro costs under Medicare in 2026

When Mounjaro is covered for diabetes, standard 2026 Part D cost-sharing applies. Your exact copay depends on your plan and which formulary tier the drug sits on, but these system-wide 2026 figures shape your total cost:

• Part D out-of-pocket cap: $2,100 for the year — once your covered drug costs reach this, you pay $0 for covered drugs the rest of the year.
• National base beneficiary premium: $38.99 per month (your plan's actual premium may be higher or lower).
• Late enrollment penalty: if you go without Part D or other creditable drug coverage, you pay 1% of $38.99 for each full month you were uncovered, rounded to the nearest $0.10, added to your premium for life.
• Part D IRMAA: higher-income beneficiaries pay an extra $14.50 to $91.00 per month on top of the plan premium when 2024 income (MAGI) exceeds $109,000 for a single filer or $218,000 for a joint return.
• Extra Help (Low-Income Subsidy): if you have limited income, this program can lower or eliminate your Part D premium, deductible, and copays — reducing what you pay for a covered diabetes drug like Mounjaro.

How to check your plan — and what to do if it's not covered

Because coverage varies so much from plan to plan, the only reliable way to know is to check your own plan directly. Use the plan finder at Medicare.gov, search your plan's formulary, or call the number on your plan card and ask specifically whether Mounjaro is covered, what tier it is on, and whether prior authorization or step therapy applies.

• If your plan doesn't cover it, ask your doctor about other diabetes drugs on your plan's formulary that may work for you.
• Check whether the manufacturer offers a savings program (note: manufacturer copay cards generally cannot be used with Medicare).
• If you were prescribed Mounjaro for weight loss, ask whether you qualify for the GLP-1 Bridge with a covered drug (Wegovy, Foundayo, or Zepbound KwikPen) instead.
• If cost is the barrier, see whether you qualify for Extra Help to lower your Part D out-of-pocket costs.