Medicare and Insulin: What You’ll Pay

The $35 Rule in Plain Terms

The Inflation Reduction Act set a cap on what Medicare enrollees pay for insulin. For a covered insulin product, you pay no more than $35 for a one-month supply. The cap applies whether the insulin is covered under Part D, which handles most insulin, or under Part B, which handles insulin used in certain pumps. And because the deductible does not apply to insulin, you pay the capped amount from your first fill of the year, even if your plan has a deductible for other drugs.

A few details are worth knowing:

• It is per product, per month. If you use two different covered insulins, such as a long-acting and a mealtime insulin, the cap applies to each one. So two insulins can cost up to twice the cap each month. The cap is not a combined limit for all your insulin.
• It scales with longer supplies. If you get a two- or three-month supply, your cost cannot be more than $35 for each month of that supply of each covered product. Generally, that means no more than two or three times the monthly cap for a single insulin.
• Your plan can charge less. The $35 is a ceiling. Some plans set lower copays for insulin.
• It applies to covered insulin. If your plan does not cover a particular insulin, the cap does not apply to that product. More on that below.

Which Part of Medicare Pays for Your Insulin

How you take insulin	Paid by	Monthly cap applies?
Pen, vial or syringe	Part D	Yes, per product
Traditional external pump	Part B	Yes, and no Part B deductible
Patch or disposable pump	Part D	Yes for insulin; the pump may cost more
Inhaled insulin	Part D	Yes, per product
Syringes, needles, swabs	Part D	No, plan cost sharing

The cap works the same way, but the part of Medicare that pays depends on how you take the insulin. Medicare’s diabetes booklet explains the split.

• Part D covers insulin you inject with a pen or syringe, insulin used with certain disposable or patch pumps, and inhaled insulin.
• Part B covers insulin used with a traditional external insulin pump that qualifies as durable medical equipment, along with the pump itself. The $35 limit applies to insulin in these pumps, and the Part B deductible does not apply to that insulin.

Insulin pens and pump supplies are a place where the rules can feel arbitrary. For example, Part B does not cover insulin pens, syringes, needles, alcohol swabs or gauze. Those fall to Part D. Our guide to Medicare Part D explains how drug plans work in general, and our post on diabetes supplies and continuous glucose monitors covers the equipment side.

What the Cap Does Not Cover

This is where people get surprised. The $35 limit is for insulin itself. It does not reduce what you pay for:

• Other diabetes medicines. Metformin, newer injectable and oral medicines and other drugs you may take are covered under your plan’s regular tiers and cost sharing, and your Part D deductible can apply to them. If you take a GLP-1 medicine, read our post on Medicare coverage of weight loss drugs, because coverage depends on the reason it is prescribed.
• Injection supplies. Syringes, needles, swabs and gauze are covered by Part D plans, but you pay the plan’s cost sharing and the deductible may apply.
• The pump itself, if it is a patch pump. If your Part D plan covers a pump that is not durable medical equipment, the pump may cost more than $35, according to Medicare.
• Test strips, meters and CGMs. Those are Part B equipment, with the deductible and 20% coinsurance that usually applies.
• Insulin your plan does not cover. If your product is not on the plan’s formulary, you may pay full price unless you get an exception.

Put differently, your insulin may be capped at $35 while the rest of your diabetes spending still follows the normal rules. Add up the whole picture rather than focusing on the one number.

Your Plan’s Formulary Is the Real Gatekeeper

Every Part D plan, including those built into Medicare Advantage plans, has a formulary, which is its list of covered drugs. Part D plans do cover insulin, but the specific brands, pens and vial formulations a plan includes can differ. A plan may cover one brand of mealtime insulin and not another, or may cover a product with extra rules such as prior authorization or a requirement to try another product first.

That means the best way to protect yourself is to check the plan, not just the cap:

• Look up your exact insulin products, including the form (vial, pen or cartridge) and strength, in the plan’s formulary.
• Confirm that your pharmacy is in the plan’s network, and ask whether a preferred pharmacy would cost you less.
• Ask whether the product needs prior authorization or has a quantity limit.
• Check again each fall, because formularies change from year to year. Our post on formulary changes explains how to do it, and our plan comparison checklist puts it in context with the rest of your decision.

If your plan does not cover the insulin your doctor prescribes, you or your doctor can ask the plan for a coverage exception. You generally need a supporting statement from your prescriber explaining why alternatives are not appropriate. If the plan says no, you have the right to appeal.

When You Also Have Extra Help

If you receive Extra Help with Part D costs, you generally pay less than the $35 cap for covered insulin, according to Medicare’s own diabetes booklet. Because Extra Help also removes the Part D deductible and lowers copays on other drugs, it can make a significant difference if you take several medicines. Read our guide on who qualifies for Extra Help. Some people who never applied are surprised to learn they would qualify.

Beyond Insulin: Your Total Drug Costs

Because the cap is narrow, it helps to understand the other protections in Part D. A separate annual limit on out-of-pocket spending for covered drugs applies once you reach it, and it is set each year. Insulin spending counts toward it, because you are paying for covered drugs. Our post on the Part D out-of-pocket cap explains how that works.

If your costs are lumpy, with high bills early in the year, the Medicare Prescription Payment Plan lets you spread out what you owe across monthly payments instead of paying everything at the counter. You can read about it in our guide to the Medicare Prescription Payment Plan. It does not reduce what you owe, but it can make the timing easier to handle.

Medicare is also negotiating prices for certain expensive brand-name drugs, including some diabetes medicines, with negotiated prices taking effect in stages under the law. The first took effect at the start of 2026. Ask your plan how negotiated prices affect the drugs you use.

When You Are in the Hospital

Insulin you receive during a covered inpatient hospital stay is generally part of the hospital care that Part A pays for, rather than something billed separately under Part D. The same is generally true during a covered stay in a skilled nursing facility. The $35 monthly cap is about what you pay at the pharmacy for the insulin you take at home.

Practical Steps if You Pay More Than Expected

Occasionally someone is charged more than $35 for a covered insulin. Here is what to do:

• Ask the pharmacist to check how the claim was processed, and confirm the plan name and the product.
• Call the number on the back of your plan card and ask whether the cap was applied. Ask for the claim to be corrected if it was not.
• If you are in a Medicare Advantage plan, check whether you were using an in-network pharmacy.
• If you cannot resolve it, call 1-800-MEDICARE, or contact your State Health Insurance Assistance Program. In Ohio that is OSHIIP.

Frequently Asked Questions

Is the $35 insulin cap the same under every Medicare plan?

The cap applies to covered insulin in Part D plans, including those inside Medicare Advantage, and to insulin used in covered pumps under Part B. Your plan can charge less than $35, but not more, for a covered product.

Does the $35 limit apply before I meet my Part D deductible?

Yes. The deductible does not apply to covered insulin, so you pay the capped amount even if you have not paid your deductible for other drugs.

What if I use two kinds of insulin?

The cap applies to each covered insulin product. If you use a long-acting and a rapid-acting insulin, you could pay up to $35 for each per month.

Does the cap apply to my insulin pump?

Insulin used in a traditional pump covered under Part B is capped at $35 per month, but the pump itself is durable medical equipment with Part B deductible and coinsurance. A patch pump covered by Part D may cost more than $35.

Does the cap apply if I have Medigap but not a drug plan?

The cap works through a Part D plan, and Medigap policies do not cover prescription drugs. Without a drug plan, you may pay full price for insulin you inject, and you could face a late enrollment penalty if you join one later.