What the Part D Out-of-Pocket Cap Means for You

What the Cap Is, in One Paragraph

For many years Part D had no ceiling on what a person could spend on drugs in a year. That changed with the Inflation Reduction Act, which built a yearly out-of-pocket cap into the benefit beginning in 2025. The cap is indexed, meaning it is adjusted over time, and it has risen from one year to the next. Because the exact figure changes, this post does not quote it. The Medicare.gov page on Part D costs lists the amount for the plan year you are shopping for, and the Plan Finder uses it when it estimates your costs.

The principle is what matters here. There is now a point at which your spending on covered drugs stops, and everything you would otherwise pay after that point is covered.

How the Benefit Works From January to December

Stage	What you pay
Deductible	Full cost until you meet the plan’s deductible (some plans have none)
Initial coverage	Your share, up to 25 percent coinsurance in the standard benefit, until you reach the cap
Catastrophic	Nothing for covered drugs for the rest of the year

Understanding the cap starts with knowing the phases of Part D, because the cap is the finish line of the second phase. According to Medicare.gov and KFF, the redesigned benefit has three stages.

• Deductible stage. At the start of the year, you may pay the full cost of your drugs until you reach your plan’s deductible. Plans may have a deductible up to a federal maximum, and some have none or apply it only to higher tiers. Check your plan.
• Initial coverage stage. After the deductible, you pay your share, which is up to 25 percent coinsurance in the standard benefit, until your out-of-pocket spending on covered drugs reaches the annual cap. Plans can charge flat copays instead of coinsurance on some tiers.
• Catastrophic stage. Once you reach the cap, you pay nothing for covered Part D drugs for the rest of the calendar year.

The earlier version of the benefit had a coverage gap, the so-called donut hole, and a catastrophic stage where you still paid a percentage. Both are gone. The redesign replaced them with the cap, which is why you may hear people say the donut hole no longer exists.

The count restarts each January 1. If you reach the cap in October, you do not carry the free status into the next year. The deductible and the cap begin again.

What Counts Toward the Cap

The out-of-pocket total that gets you to the cap is made up of what you, and certain others on your behalf, pay for covered drugs. Medicare.gov says it includes your copayments, coinsurance, and certain payments made through assistance programs. That can include:

• The deductible you pay.
• Copays and coinsurance for covered drugs during the initial coverage stage.
• Payments made for you through Extra Help, the low-income subsidy.
• Payments made on your behalf by certain other programs, such as some state pharmaceutical assistance programs, and by family members or friends, in many cases.

The qualifier is “covered drugs.” The cap tracks spending on drugs that are on your plan’s formulary and that you fill under the plan’s rules.

What Does Not Count

The exclusions are where people get caught. According to Medicare.gov and CMS guidance, your plan’s monthly premium is not included in the out-of-pocket calculation. You keep paying the premium all year, whether or not you reach the cap.

Other items generally do not count either.

• Drugs the plan does not cover. If a drug is not on the formulary and you pay for it yourself, that spending does not count toward the cap, and you stay exposed to its full price unless you win an exception.
• Drugs Part D cannot cover by law. Weight-loss drugs have long been excluded from Part D by law. A temporary federal program that began in mid-2026 now offers some eligible people certain weight-loss drugs, but it runs outside your plan’s regular drug benefit, and according to Medicare.gov what you pay through it does not count toward the cap. Our post on Wegovy, Zepbound, and similar drugs explains.
• Medicines you buy outside your plan, for example using a discount card or coupon, are generally not counted, because the claim does not run through your Part D benefit. Ask your plan how it treats those purchases before you assume.
• Drugs covered under Part B rather than Part D, such as many infusions and injections given in a doctor’s office. Those carry the Part B 20 percent coinsurance and do not count toward your Part D cap.
• Costs for services that are not drugs at all, such as hospital or doctor bills.

For a closer look at how drug coverage fits into the rest of Medicare, see our guide to Medicare Part D.

Who Benefits Most, and Who Barely Notices

A cap is insurance against a heavy drug year, and its value depends on how much you use.

If you take several brand-name or specialty drugs, or one very costly drug, you are likely to reach the cap partway through the year. For you the cap is significant. It sets a ceiling on your annual exposure and gives you a predictable maximum. KFF notes that a hard cap was the point of the redesign, since the previous benefit had no limit for people with the highest drug costs.

If you take a few inexpensive generics, you may never come near the cap. Your yearly drug cost is already low, and what matters for you is the premium and the copays on the lower tiers. For you, the cap is a safety net you hope never to use.

In between are people on one or two mid-priced drugs, who may or may not reach it, depending on tier and plan design. The only way to know is to price your own drug list. Plan Finder will estimate your year-end total if you enter your drugs and pharmacy.

A related point is timing. People on costly drugs tend to reach the cap earlier in the year, which means the first few months have the highest pharmacy bills and the later months can be free. If that pattern strains your budget, the Medicare Prescription Payment Plan, described below, may help.

The Medicare Prescription Payment Plan: Cap Versus Cash Flow

The cap limits the total you pay over the year. It does not reduce what you pay at the pharmacy counter in any single month. A person with a very costly drug could face a large bill in January, and then pay nothing for the rest of the year.

The Medicare Prescription Payment Plan is an option designed to address that. Beginning in 2025, Part D plans are required to offer it. It lets you spread your out-of-pocket drug costs across the year in monthly installments instead of paying them at the pharmacy. It does not reduce the total you owe, and it is not insurance. It smooths timing. You generally sign up through your plan, and it is worth asking your plan how enrollment works, what happens if you leave the plan mid-year, and whether it makes sense for your pattern of spending. Our overview of Part D describes the basics, and your plan can tell you the details.

Why the Cap Does Not Mean All Plans Are Equal

It is tempting to conclude that, with a cap in place, comparing Part D plans matters less. In most cases, it matters just as much. Here is why.

The cap applies to every Part D plan, so your worst-case drug spending is similar across plans for covered drugs. But the cap is a ceiling, and you may spend far less than the ceiling in a typical year. Where you land below it depends on the plan’s formulary, your tier, your deductible, and your pharmacy.

Premiums also differ. You pay the premium all year, and the cap does nothing about it. The drug list differs too, and the cap only counts covered drugs. A plan that does not cover your key medication offers you no protection on that drug at all. And plans can add prior authorization, step therapy, and quantity limits that determine whether you can get the drug you want. Our post on checking your drugs before open enrollment ends walks through those checks.

Because plans now carry a larger share of the cost of expensive drugs, premiums, formularies, and rules can change from year to year. That is one more reason to read your Annual Notice of Change instead of assuming last year’s plan still fits.

Changing Plans Mid-Year and the Cap

If you switch Part D plans during the year, which is possible only in certain situations, your out-of-pocket spending generally carries over, because the cap follows the person rather than the plan. According to CMS guidance, plans pass the running total along when you change plans during the year, and a new plan should count it. The new plan’s own deductible and cost-sharing rules still apply, though, so your costs under it can look different. If you are in that situation, check with the new plan that it has your accumulated total, and keep your own records of what you paid. For most people, though, the question comes up during the fall window, when changes take effect January 1 and the count restarts anyway. Our overview of the Annual Enrollment Period describes that calendar.

Other Protections That Work Alongside the Cap

The cap is one of several changes to drug coverage. Recommended vaccines now carry no cost-sharing under Part D, a topic we cover in our post on shingles, flu, and RSV vaccines. There is also a separate monthly limit on cost-sharing for covered insulin. And Extra Help, which assists people with limited income and resources, has been expanded. If your income is limited, ask whether you qualify, because Extra Help can reduce premiums, deductibles, and copays. The Social Security Administration handles applications. For free counseling in Ohio, the Ohio Senior Health Insurance Information Program, OSHIIP, can walk you through the options.

Frequently Asked Questions

What is the Part D out-of-pocket cap?

It is an annual limit on what you pay out of pocket for covered Part D drugs. Once you reach it, you pay nothing for covered drugs for the rest of the calendar year. The amount is adjusted over time, so check Medicare.gov for the figure that applies to your plan year.

Does my Part D premium count toward the cap?

No. The premium is separate. You pay it all year whether or not you reach the cap.

Does the cap apply to drugs my plan doesn’t cover?

No. Only spending on covered drugs counts. If the plan does not cover a drug, that cost does not move you toward the cap.

Does the cap reset each year?

Yes. The count starts over each January 1, along with your deductible.

Is the cap the same as the Medicare Prescription Payment Plan?

No. The cap limits your total yearly spending on covered drugs. The Medicare Prescription Payment Plan spreads what you owe across monthly payments so you do not pay it all at the pharmacy.