Medicare drug plans do cover Mounjaro, and the reason is the diagnosis: Mounjaro is tirzepatide, and its label is for type 2 diabetes. The label covers blood sugar control in adults and children 10 and older with type 2 diabetes[1]. It also covers cutting the risk of heart attack, stroke and cardiovascular death in adults with type 2 diabetes at high risk[1].
How often plans list it, and the paperwork they ask for
A study of every Medicare Part D formulary, weighted by enrollment, tracked injectable tirzepatide from its first appearance[2]. Coverage rose from 26.5% in the third quarter of 2022 to 92.9% in the third quarter of 2024[2]. Over the same period, prior authorization among covering plans stayed under 25% until late 2023, then rose to 83.2%[2]. Coverage was consistently higher in Medicare Advantage drug plans than in standalone drug plans[2]. The same study’s semaglutide figures are in does Medicare cover Ozempic.
In practice that means your prescriber will likely send a form showing the diagnosis before the pharmacy can bill the plan. The authors found no difference in coverage or prior authorization between dose levels[2].
What you pay through the year
| Stage | 2026 | 2027 |
|---|---|---|
| Deductible (the most any plan may set) | $615 | $700 |
| After the deductible | 25% coinsurance | 25% coinsurance |
| Yearly out-of-pocket limit, covered drugs | $2,100 | $2,400 |
Part D works in stages. If your plan has a deductible, you pay the full cost of covered drugs until you reach it; after that you pay 25% coinsurance until your out-of-pocket spending reaches $2,100 in 2026[3]. The figures in the table are the limits every plan works within; your own plan’s tier for Mounjaro decides the actual copay or coinsurance inside them.
If a large bill early in the year is the problem, Lilly’s Mounjaro page points Medicare enrollees to the Medicare Prescription Payment Plan[4]. It is a free option that spreads prescription costs into monthly payments over the plan year[4]. Lilly’s page says you can opt in at any time[4].
What Medicare enrollees cannot use
Lilly’s savings card, which can take a commercially insured patient’s fill down to $25, excludes anyone enrolled in Medicare, Medicare Part D, Medicare Advantage or Medigap[4]. The card is for commercial insurance only, so on Medicare the plan’s cost-sharing is the price.
The newer Medicare GLP-1 Bridge is not a route either. It charges $50 a month from July 1, 2026 for Foundayo (tablet), Wegovy (injection or tablet), Zepbound (KwikPen only), and Mounjaro is not on that list[5]. It also turns away anyone with type 2 diabetes, moderate-to-severe sleep apnea or fatty liver disease, and anyone whose plan already pays for a GLP-1 drug, tirzepatide included[5]. Its weight-loss rules are set out in does Medicare cover Zepbound.
Price negotiation
CMS has negotiated Medicare prices for 10 drugs from 2026 and 15 from 2027, and on its list for 2027 is a single entry covering Ozempic, Rybelsus and Wegovy[6]. It selected 15 more for its third cycle, with prices from 2028, and Trulicity is on it[7]. Mounjaro is on none of the three lists[6][7]. Lilly’s two diabetes drugs are compared in Trulicity vs Mounjaro.
Questions to ask your plan
Before the first fill, ask your plan three things. Which tier does Mounjaro sit on? Does it need prior authorization, and what diagnosis must the form show? And does the plan want a preferred alternative tried first? If it prefers a rival, the price comparison is in Mounjaro vs Ozempic.