Medicare Cancer Treatment Coverage: Chemo, Radiation & More (2026)

Medicare covers cancer treatment, and which part pays turns on where and how you're treated. Part A covers an inpatient stay. Part B covers outpatient chemotherapy, radiation, and doctor visits. Part D covers the cancer drugs your drug plan covers. In 2026 the Part A inpatient deductible is $1,736 per benefit period, outpatient chemotherapy and radiation cost 20% of the Medicare-approved amount after a $283 Part B deductible, and once your out-of-pocket spending on covered Part D drugs reaches $2,100 you pay no cost sharing on those drugs for the rest of the calendar year. This guide breaks down each part and what you'll actually owe.1,2

How Medicare splits cancer treatment coverage

Cancer treatment rarely fits into a single category. A patient might receive IV chemotherapy at an outpatient clinic on Tuesday, take an oral drug at home every day, and have a follow-up scan in the same week. Medicare covers all of these, but the billing runs through different parts depending on the setting.

The dividing line is largely where you receive care: a hospital admission runs through Part A, and outpatient treatment, including most chemotherapy and radiation given at a clinic or doctor's office, runs through Part B. A cancer drug you take by mouth is the exception. It may be billed under Part B or covered by your Part D drug plan, and the setting alone doesn't tell you which, so that one is a question for your oncologist and your plan.1

Part A: inpatient chemotherapy and radiation

When cancer treatment requires a hospital admission, Part A pays. This includes chemotherapy administered during an inpatient stay, inpatient radiation, and any other cancer-related care delivered while you're admitted as a hospital inpatient.

Under Part A, you pay the inpatient hospital deductible of $1,736 per benefit period in 2026. CMS states that deductible covers your share of costs for the first 60 days of Medicare-covered inpatient hospital care in a benefit period. From day 61 through day 90, a daily coinsurance of $434 applies. Coverage does not simply stop at day 90: beyond it you can draw on lifetime reserve days at $868 per day, up to a 60-day lifetime maximum, and once those are exhausted you pay the full cost.1,3

The more common scenario is outpatient infusion, which runs through Part B instead. Our cancer chemotherapy guide covers that setting in more depth.

Part B: outpatient chemotherapy and radiation

Part B covers chemotherapy you receive in a hospital outpatient department, your oncologist's office, or a freestanding infusion clinic. Per the CMS 2026 cost announcement, the cost structure is:1

• Annual Part B deductible: $283 (paid once per year, not per treatment)1
• Coinsurance: 20% of the Medicare-approved amount for each session1
• Hospital-outpatient copayment limit: for chemotherapy received in a hospital outpatient setting, medicare.gov states your copayment won't be more than the inpatient hospital deductible amount ($1,736 in 2026)1

Read that last one carefully: it is easy to mistake for a cap on your treatment costs, and it isn't one. The same page says the specific amounts you could owe depend on other insurance you may have, how much your doctor charges, whether your doctor accepts assignment, the type of facility, and where you get your test, item, or service.1

Outpatient radiation therapy follows the same structure: 20% after the $283 deductible.1

A worked example: what Medicare cancer treatment actually costs

Say you're on Original Medicare and your oncologist orders six outpatient infusion sessions at a hospital outpatient department. Assume, as an illustration, that the Medicare-approved amount is $2,000 per session (your real rate depends on the drug and the facility). Here is roughly how the math runs in 2026:1

• Session 1: You first meet the $283 annual Part B deductible. On a $2,000 session, that's $283 plus 20% of the remaining $1,717, or about $343 more, so roughly $626 for the first session.1
• Sessions 2 onward: The deductible is done. You pay 20% of the $2,000 Medicare-approved amount, or $400 per session.1
• The copayment limit. For chemotherapy in a hospital outpatient setting, medicare.gov states your copayment won't be more than $1,736, the inpatient deductible amount, even as the 20% coinsurance keeps adding up across sessions.1

The dollar figures above ($2,000 per session) are a hypothetical illustration, not a Medicare rate. What the program fixes is the $283 deductible and the 20% coinsurance; what you actually owe on top of that depends on other insurance you have, what your doctor charges, whether your doctor accepts assignment, and the type of facility. Separately, if you also take a cancer drug your Part D plan covers, your cost sharing on covered drugs stops once your counted out-of-pocket spending reaches $2,100 for the year.1,2

Part D and oral cancer drugs: the $2,100 cap

Cancer drugs you take by mouth are where the biggest change for Medicare beneficiaries happened in recent years. Under the Inflation Reduction Act's Part D redesign, the standard 2026 benefit runs in three phases and the old coverage gap (the "donut hole") is gone. You pay your plan's deductible first, which no plan may set above $615 in 2026, then 25% coinsurance on covered drugs. Once your out-of-pocket spending reaches the annual threshold of $2,100, you pay no cost sharing on covered Part D drugs for the rest of the calendar year, per CMS.2,1

For cancer patients on expensive drugs, this is a substantial protection. Some targeted therapy drugs and oral chemotherapy agents carry list prices of several thousand dollars a month, and under the old Part D structure patients could face crushing annual costs. Two limits are worth knowing before you treat $2,100 as your total. It covers cost sharing on drugs your plan covers, so a drug your plan excludes doesn't count toward it, and your plan's monthly premium keeps running after you reach it. The threshold ends cost sharing, not everything you pay for drug coverage.2

A worked example: what an expensive cancer drug actually costs you. Suppose you're prescribed an oral targeted therapy, like one of the tyrosine-kinase inhibitors used for chronic myeloid leukemia (CML), with a list price of several thousand dollars a month, and your Part D plan covers it. What you pay for that drug counts toward the $2,100 annual out-of-pocket threshold, and so do certain payments made on your behalf, such as payments through Extra Help, which means you reach the threshold on the counted total rather than on your own cash alone. Once your counted covered-drug spending reaches $2,100 for the year, you pay no cost sharing on covered drugs the rest of the year, however high the list price.2 Three things can soften even that $2,100: if the cost lands early in the year, the Medicare Prescription Payment Plan lets you spread it into level monthly installments; if your income is limited, Extra Help lowers it further; and if the drug turns out to bill under Part B instead, a different set of costs applies, which is worth asking your oncologist about. So for a covered drug on Original Medicare with a Part D plan, your cost sharing for the year lands at or below $2,100, often far less, plus whatever your plan charges in premium.2,4

One important distinction: a cancer drug you take by mouth is not automatically a Part D drug. Whether it is billed under Part B or under Part D decides which set of costs applies, the 20% Part B coinsurance or your drug plan's deductible and coinsurance, and on an expensive drug that is a large difference. The coverage basics above do not settle it for any particular drug, so ask your prescribing oncologist and your Part D plan which part covers yours before the first fill.1

The Medicare Part D redesign guide goes into the full phase structure if you need it.2

Extra Help with Part D drug costs

Even a $2,100 cap can be hard to absorb for a cancer patient on a fixed income. If your income and resources are limited, you may qualify for Extra Help, also called the Part D Low-Income Subsidy (LIS), a federal program run by the Social Security Administration that sharply lowers what you pay for covered drugs. Under Extra Help both your plan premium and your plan deductible are $0. One condition travels with the premium subsidy: it is based on your region's benchmark premium, so if you pick a plan that costs more than the benchmark, you owe the difference.4

For 2026, full Extra Help is available to individuals with income below about $1,995 a month ($23,940 a year) and married couples with income below about $2,705 a month ($32,460 a year), within the program's resource limits. Those are the limits for the 48 contiguous states and DC; Alaska and Hawaii are higher. Enrollees who qualify pay no more than $5.10 for each covered generic drug and $12.65 for each covered brand-name drug in 2026, and no cost sharing at all once out-of-pocket drug costs reach the $2,100 threshold. Those two copay figures are a ceiling rather than a flat price: if you also have full Medicaid, you pay $1.60 for a generic and $4.90 for a brand-name drug at or below 100% of the Federal Poverty Level, and nothing at all for either if you are in an institution or receiving home and community-based services. One warning if you are holding SSA's Extra Help leaflet (Publication No. 05-10508): do not screen yourself out on the income limits it prints. Its January 2026 edition still shows $23,475 for one person and $31,725 for a married couple, which are last year's figures. If your income is above those but at or below $23,940 (or $32,460 for a couple), you are inside the 2026 limit and should apply anyway. You can apply through the Social Security Administration at ssa.gov/extrahelp or by calling Social Security at 1-800-772-1213 (TTY 1-800-325-0778). Extra Help isn't available in Puerto Rico, the U.S. Virgin Islands, Guam, the Northern Mariana Islands, or American Samoa; if you live there, contact your state Medicaid office instead.4,5

Clinical trials

If you're taking part in a clinical research study, Medicare covers some of the costs. Its clinical research studies page states that Part A and Part B "cover some costs, like office visits and tests." On your own share, medicare.gov says you may pay 20% of the Medicare-approved amount depending on the treatment you get, and that the Part B deductible may apply.1

What medicare.gov does not settle, in either direction, is whether Medicare pays for the study treatment itself. That page describes only "some costs" and states no rule about the investigational treatment, so don't assume it's covered and don't assume it isn't. Ask the study's research coordinator what the sponsor pays for and what will be billed to your Medicare before you enroll, and ask your own doctor too: medicare.gov warns that a doctor may recommend services Medicare doesn't cover, or offers too frequently, which could end up costing you more.1

To find a study, medicare.gov points to the National Institutes of Health's ClinicalTrials.gov and the National Cancer Institute's clinical trials listings. Those help you locate a trial; neither is a coverage decision about one. Our clinical trials guide has more.1

What Medicare Advantage plans cover

If you're on a Medicare Advantage (MA) plan rather than Original Medicare, the plan covers all the same cancer treatments (chemotherapy, radiation, oral drugs) because MA plans must cover everything Original Medicare covers. The difference is in the cost-sharing details, prior authorization requirements, and network.

MA plans typically have their own copayment structures for chemotherapy and radiation rather than the standard 20% coinsurance. Some plans have lower per-visit costs; others have higher total out-of-pocket limits. CMS sets a maximum out-of-pocket limit each year that plans may not exceed, and for 2026 it is $9,250 for in-network Part A and Part B cost sharing; plans may set lower limits. Two conditions on that number matter to a cancer patient. Part D drug cost sharing does not count toward it, so your drug spending runs on the separate $2,100 Part D track rather than inside the $9,250. And a plan that covers out-of-network care, such as a PPO, sets two annual limits: one for in-network costs and a second, higher one for combined in-network and out-of-network costs.3,2

Prior authorization and your right to appeal

Your plan may require prior authorization, meaning approval in advance, before certain cancer treatments, particularly expensive drugs or newer therapies. That isn't a denial, but your oncologist may need to go through an approval process first, so ask the plan and your care team about it before treatment begins.

If your MA plan denies prior authorization or refuses to cover a treatment, you have the right to appeal. You can request a standard appeal, or, when waiting for a standard decision could seriously jeopardize your life, health, or ability to regain maximum function, an expedited (fast) appeal, which the plan must generally decide within 72 hours.6 Your plan's denial notice explains how to file. For a Medicare Advantage plan you generally have 65 days from the date on that notice to ask the plan to reconsider, and missing it is not automatically the end: you can still file if you give a reason for filing late. The guide to appealing a Medicare denial walks through all five levels.6 For free, one-on-one help understanding a denial and filing an appeal, contact your State Health Insurance Assistance Program (SHIP), a federally funded counseling service. Find your local SHIP with the locator at shiphelp.org or by calling 1-877-839-2675. Many states run the program under a different name, such as HICAP, SHINE, SHICK, or VICAP.7

Planning for Medicare cancer treatment costs

Between Part B coinsurance and Part D drug costs, cancer treatment on Medicare involves real out-of-pocket exposure. A few things help.

If you have Original Medicare, a Medigap (Medicare Supplement) policy can cover the 20% Part B coinsurance on chemotherapy and radiation, which can eliminate most of your outpatient treatment costs. How much of that coinsurance a policy picks up depends on the plan letter you buy: Plan G, for example, pays the Part B coinsurance, along with the Part A deductible and coinsurance. Medigap plans are standardized and federally regulated, so a given plan letter offers the same benefits no matter which carrier sells it.8

Timing is the part to understand before you count on Medigap, and it matters most to someone who has just been diagnosed. The federal Medigap Open Enrollment Period is a one-time six-month window that starts the first month you are both 65 or older and enrolled in Part B. During it, an insurer can't refuse to sell you any policy it offers, can't use medical underwriting to deny you coverage because of pre-existing health problems, and can't charge you more because you have them. Even inside that window, an insurer may still decline to cover your out-of-pocket costs for a pre-existing condition for up to six months, unless you had at least six months of continuous prior creditable coverage. The guide to what Medicare doesn't cover has more on how Medigap works.8

If your income is limited, you may qualify for a Medicare Savings Program through your state's Medicaid agency, which can pay your Part B premium and in some cases your coinsurance; Medicare explains the four programs and how to apply. For help with drug costs specifically, apply for Extra Help through the Social Security Administration at ssa.gov/extrahelp. See the dual eligibility guide for how these fit together.

For Part D drug costs, the $2,100 annual threshold applies whatever your income. If you reach it, your cost sharing on covered drugs stops for the rest of that year, though your plan premium continues. If your drug costs are high early in the year, the Medicare Prescription Payment Plan (M3P), an official Medicare program every Part D and Medicare Advantage drug plan must offer, lets you spread your out-of-pocket payments across the calendar year in monthly installments rather than paying in full at the pharmacy. M3P doesn't lower your total drug costs; it changes when you pay them.2

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The information on Brevy.com is for educational purposes only and is not a substitute for professional legal, financial, or medical advice. Rules vary by state and program and change frequently. Always verify with the relevant agency or a qualified professional. Brevy is not a law firm, financial advisor, or healthcare provider.