A decade ago, seniors on insulin sometimes paid $500 or more a month for it. Some rationed doses. Some stopped taking it. That is over. Medicare now caps insulin at $35 per month per prescription. Here is how the cap works, who gets it, and what to do if your pharmacy charges you more.
The short answer
Since January 1, 2023, every Medicare Part D plan and every Medicare Advantage plan with drug coverage must cap covered insulin at $35 per month per prescription. There is no deductible on covered insulin. The cap applies from the first fill of the year.
This came from the Inflation Reduction Act (IRA), signed in 2022. It also removed the deductible on insulin and later added the $2,000 out-of-pocket cap on all Part D drugs.
What the Inflation Reduction Act did for Medicare
The IRA made several changes to Medicare prescription drugs. Insulin was the first big one to hit. The full picture:
- 2023: $35 monthly cap on covered insulin, no deductible
- 2023: Free adult vaccines under Part D (shingles, Tdap, others)
- 2024: Elimination of the catastrophic-phase 5% coinsurance
- 2024: Expanded Extra Help program eligibility to 150% of the federal poverty level
- 2025: $2,000 annual out-of-pocket cap on Part D drugs
- 2026: First round of Medicare-negotiated drug prices takes effect
The insulin cap was the piece most people noticed first because so many seniors take insulin daily.
Which insulins qualify
Every Medicare Part D plan must cover at least one insulin from each of the main insulin groups: rapid-acting, short-acting, intermediate-acting, and long-acting. That means every plan has to have a $35 option in each category.
Common insulins covered on most Part D formularies:
| Insulin | Type | Brand or generic |
|---|---|---|
| Lantus | Long-acting | Brand and biosimilars |
| Basaglar | Long-acting | Brand |
| Levemir | Long-acting | Brand |
| Tresiba | Long-acting | Brand |
| Humalog | Rapid-acting | Brand and generic |
| Novolog | Rapid-acting | Brand and generic |
| Fiasp | Rapid-acting | Brand |
| Admelog | Rapid-acting | Brand |
| Humulin N / R | Intermediate / Short | Brand and OTC |
If your insulin is on your plan's formulary, it is capped at $35 per fill. If your specific brand is not on the formulary, ask your doctor if a covered version would work. Almost every situation has a covered option.
How the cap works at the pharmacy
Very simple. You hand over your Medicare Part D or Medicare Advantage prescription card. The pharmacy runs the insulin through your plan. You pay at most $35, no matter what phase of the year you are in. No deductible, no coinsurance, no coverage gap surprises.
You get the $35 rate on every fill for the entire year. Whether it is your first fill in January or your 12th fill in December.
Insulin through a pump: the Part B side
Most insulin is billed under Part D. Insulin used in a Medicare-approved insulin pump is different. It is billed under Part B, along with the pump itself.
The IRA also capped Part B insulin at $35 per month with no deductible. So the pump route costs the same $35 out of pocket per month as pen or vial insulin under Part D.
Medigap does not usually apply here because the cap is already so low. But if the plan happens to charge coinsurance and you have Plan G, that portion is covered by Medigap.
How to make sure you get the $35 rate
Three quick checks:
- Check your plan's formulary. Log in to your Part D or Medicare Advantage plan's website and look up your insulin. If it is listed, you get the $35 cap. If not, ask about a formulary exception or talk to your doctor.
- Ask your pharmacy to rerun the claim if the price is wrong. Sometimes billing codes get mixed up. A quick re-run usually fixes it.
- Call member services if the cap does not apply. Every Part D plan has a phone number on your card. They can fix it in real time.
Common billing mistakes
The plan puts insulin in the wrong tier
Sometimes a plan miscodes an insulin as a specialty tier drug. The pharmacy charges you full price instead of $35. Fix: call the plan and ask them to correct the tier and reprocess the claim.
Insulin bought at an out-of-network pharmacy
If you use a pharmacy outside your plan's network, the $35 cap may not apply. Standard fix: transfer the prescription to an in-network pharmacy. Or ask about mail order, which usually locks in the low price.
The prescription is for insulin your plan does not cover
Off-formulary insulin does not get the $35 rate. But every plan must cover at least one insulin from each main category. Switching to a covered version usually works and your doctor can make the change.
Bought as cash without running through the plan
If you use a discount card and bypass insurance, the $35 cap does not apply. Always run insulin through Medicare first. If cash is cheaper (rare), use the cheaper option.
How the cap fits with the $2,000 Part D cap
Two separate protections working together. The $35 insulin cap applies at each fill. The $2,000 annual Part D cap applies to all your Part D spending combined.
What you pay for insulin counts toward the $2,000 annual cap. Once you have paid $2,000 out of pocket in a year across all your Part D drugs, everything is free the rest of the year, including insulin. Most people paying only $35 a month for insulin do not hit $2,000 in a year on insulin alone, but if you take other expensive drugs, the two protections stack. See our post on the Medicare donut hole in 2026 for the full picture on the Part D cap.
Real-world example
Sylvia is 74, type 2 diabetic, takes Lantus once a day. Before 2023 her cost:
- Retail price: about $340 per month
- Plan cost sharing (before donut hole): $110 per month
- Cost during donut hole: $175 per month
- Annual out of pocket: about $1,600
Since 2023:
- Every month: $35
- Annual out of pocket: $420
- Yearly savings: roughly $1,180
If she also takes Humalog for meals, that is another $35 per month, so $840 per year for both insulins combined. Still a fraction of what she used to pay.
Extra Help makes it even cheaper
If you qualify for full Extra Help (the Part D Low Income Subsidy), insulin costs a few dollars a fill or $0. The $35 cap is the ceiling for regular members. For Extra Help members, it is often much lower.
Extra Help now applies to more people than before. Income under 150% of the federal poverty line qualifies you for full Extra Help. See our post on Extra Help with Medicare Part D for how to apply.
The bottom line
The $35 insulin cap is one of the clearest wins from the Inflation Reduction Act. Every Medicare Part D plan and Medicare Advantage drug plan has to follow it. If you pay more than $35 for a covered insulin, something is coded wrong. Fix it before you leave the pharmacy.
Combined with the $2,000 out-of-pocket Part D cap, expanded Extra Help, and free vaccines, Medicare drug costs are the lowest they have been for insulin users in decades.
Not sure which Part D plan best covers your insulin and other drugs? See our guides on picking a Part D plan and Medicare diabetes coverage in 2026. The Medicare.gov Plan Finder lets you compare Part D plans by your exact medications. Or book a free call and we will run the numbers together.
Frequently asked questions
How much is insulin under Medicare in 2026?
$35 per month per covered prescription. No deductible. Applies to every Part D plan and every Medicare Advantage plan with drug coverage.
Which insulins qualify for the $35 Medicare cap?
All insulins on your plan's formulary. Every plan must cover at least one insulin in each main category.
Does the $35 insulin cap apply to Medicare Advantage plans?
Yes. Every Advantage plan with drug coverage caps insulin at $35 the same way a stand-alone Part D plan does.
Does the $35 cap apply to insulin from a pump?
Yes. Pump-supplied insulin is under Part B and is also capped at $35 per month with no deductible.
What if my pharmacy charges more than $35?
Call your plan and ask them to correct the billing. Most cases are formulary or tier coding errors. Refunds are common.
Does the Extra Help program work with the insulin cap?
Yes. Full Extra Help drops insulin to a few dollars or $0 per fill. Partial Extra Help keeps you at $35 or below.