Two newer medicines can slow early Alzheimer's disease a little: lecanemab (Leqembi) and donanemab (Kisunla). Both remove amyloid (a sticky protein that builds up between brain cells). They do not cure the disease, and they are expensive.^1,5,6

The drug is only part of the bill. Treatment also means brain scans, tests, clinic visits and many trips to an infusion center. This page explains what Medicare pays, what you may owe, and where to look for help. Prices and rules change often. The facts here are current as of October 2026.

Key points

Medicare Part B can cover Leqembi and Kisunla IV infusions for people with early Alzheimer's and confirmed amyloid. Your doctor must send your health data to a Medicare-approved registry.^1,2
After the yearly Part B deductible ($283 in 2026), you usually pay 20% of the Medicare-approved amount. Original Medicare has no yearly cap on that share.^3,9
At list price, 20% could mean roughly $5,000 to $6,500 a year for the drug alone, plus scans and visits.^5,6
A Medigap plan, Medicaid, or a Medicare Savings Program can pay some or all of your 20%.^7,8
Free help: 1-800-MEDICARE, your State Health Insurance Assistance Program (SHIP), and the Alzheimer's Association Helpline at 800-272-3900.^5,14

What the drugs cost

The drug makers set these list prices when each drug came out:

Medicine	How it is given	List price at launch
Lecanemab (Leqembi)	IV infusion every 2 weeks at first, about one hour each¹²	$26,500 a year⁵
Donanemab (Kisunla)	IV infusion every 4 weeks, about 30 minutes each¹³	$32,000 a year⁶

These are starting points, not your bill. The amount Medicare approves can differ from the list price. The real cost also depends on body weight for lecanemab, and on how long treatment lasts.^6,12 For donanemab, the doctor may stop the drug once a PET scan shows the amyloid has dropped to very low levels. That can shorten treatment and lower the total cost.¹³

Lecanemab also comes as a weekly shot you give at home with a pen, called Leqembi Iqlik.¹² It is paid for differently. See the Part D section below.

How Medicare covers these drugs

Medicare Part B is the part that pays for doctor visits and outpatient care. It also pays for most drugs a health worker gives you in a clinic, such as IV infusions.¹¹ Part B may cover Leqembi and Kisunla if all of these are true:¹

You have mild cognitive impairment or mild dementia caused by Alzheimer's disease.
A test has confirmed amyloid in your brain.
Your doctor takes part in a study or registry that Medicare has approved.

Medicare.gov is clear that these drugs may slow symptoms but do not reverse the disease.¹ To see whether treatment fits your family, read Are anti-amyloid treatments right for us?

The registry rule (CED)

Medicare calls this rule coverage with evidence development, or CED. It means Medicare pays for the drug, but only while it collects real-world data on how well it works.² The rule began in April 2022. As of the CMS page last updated in March 2026, it is still in place.²

Here is how it works for you:²

Your doctor or clinic staff enter your information into the registry. You do not fill out forms yourself.
They send data when you start, then every six months, for up to two years. That is five check-ins in all.
CMS runs its own national registry. A few other approved registries also count.

What to ask: "Does your clinic report to a Medicare-approved registry?" If the answer is no, Medicare Part B will not pay for the infusions there. Ask for a referral to a clinic that does.

What you will pay with Original Medicare

With Original Medicare, you pay the yearly Part B deductible first. In 2026, it is $283. After that, you usually pay 20% of the Medicare-approved amount.^1,3 You also keep paying the monthly Part B premium. For most people in 2026, that is $202.90.³

A rough example. If Medicare approved the full list price, 20% of $26,500 is $5,300 a year for Leqembi. 20% of $32,000 is $6,400 a year for Kisunla.^5,6 Your real share could be higher or lower.

Original Medicare has no yearly limit on what you pay out of pocket, unless you have extra coverage.⁹ That is why supplement plans and Medicaid matter so much here.

The costs beyond the drug

Medicare.gov warns that scans and tests before and during treatment can add to your costs.¹ Plan for these:

Brain MRIs. You need one before starting, then more in the first months to check for ARIA (brain swelling or small bleeds). Lecanemab calls for scans at about 1, 2, 3 and 6 months. Donanemab calls for scans before the 2nd, 3rd, 4th and 7th infusions.^12,13 Read more on ARIA.
Amyloid tests. A PET scan, spinal fluid test or blood test confirms amyloid before treatment. See brain scans, spinal fluid tests and blood tests.
APOE gene test. Your doctor may suggest this test to judge ARIA risk. See genes and dementia.
Infusion center fees. The clinic or hospital also bills for giving the infusion. What you pay depends on the type of facility.¹
Doctor visits with the specialist, often several in the first year.
Travel, parking and time off work for the family member who drives. Infusions every two or four weeks add up.

Your Part B 20% share usually applies to these covered outpatient services too.³

Amyloid PET scans. Medicare used to pay for only one amyloid PET scan in a person's lifetime, and only in a study. In October 2023, Medicare dropped both limits. Now the regional companies that handle Medicare claims decide coverage.⁴ Ask your doctor's office to check before the scan.

Do not skip MRI scans to save money. The scans catch brain swelling or bleeding early, often before symptoms. Talk with the care team about cost instead.

Call 911 for stroke-like signs, such as sudden weakness on one side, trouble speaking or a seizure. Tell the emergency team the person takes an anti-amyloid drug.

Medigap: help with the 20%

Medigap, also called Medicare Supplement Insurance, is private insurance you add to Original Medicare. It helps pay your share, such as coinsurance and deductibles.⁸

Most Medigap plans (A, B, C, D, F, G and M) pay all of the Part B 20% coinsurance.⁸
Plan N also pays it, but you may owe small copays for some visits.⁸
Plan K pays half and Plan L pays three quarters. In 2026, their yearly out-of-pocket limits are $8,000 for K and $4,000 for L.⁸

You cannot use Medigap with a Medicare Advantage plan.⁹ The rules on when you can buy a Medigap plan matter. A SHIP counselor can explain your options and timing.¹⁴

Medicare Advantage plans

Medicare Advantage plans (Part C) are run by private companies. They must cover all medically necessary services that Original Medicare covers, so they cover these drugs under the same rules.⁹

They may work differently in ways that matter for this treatment:⁹

You may need to use doctors, infusion centers and MRI centers in the plan's network.
You may need prior authorization (approval before treatment) or a referral to a specialist.
Your share may be a copay or coinsurance set by the plan.
Unlike Original Medicare, every plan has a yearly limit on what you pay for covered services. Check your plan's limit.

Call your plan before starting. Ask about the drug, the infusions, the scans and the specialist visits.

The at-home pen and Part D

Part B mainly pays for drugs you would not give yourself. Medicare drug plans (Part D) cover many drugs that Part B does not.¹¹ Because Leqembi Iqlik is a shot used at home, coverage may come through a Part D plan instead. Medicare.gov also says a Part D plan might cover these drugs when Part B rules are not met.¹

Part D has helpful limits in 2026:¹⁰

Your out-of-pocket cost for covered drugs is capped at $2,100 for the year. After that, you pay nothing for covered Part D drugs until the next year.
The Medicare Prescription Payment Plan lets you spread your costs into monthly payments. It does not lower the total, but it can prevent one big bill.

Ask your Part D or Medicare Advantage plan whether it covers Leqembi Iqlik, and at what cost.

Medicaid and Medicare Savings Programs

If your income and savings are limited, your state may help.

Medicaid. People who have both Medicare and Medicaid can get help paying the 20% coinsurance. States may add their own rules.^5,6 See our page on Medicaid and long-term care.

Medicare Savings Programs. These state programs help pay Medicare costs. The most helpful one here is the Qualified Medicare Beneficiary (QMB) program.⁷

QMB pays Part B premiums, deductibles, coinsurance and copays. Medicare providers may not bill a QMB member for covered services.⁷
In 2026, the monthly income limit for QMB is $1,350 for one person or $1,824 for a married couple. The savings limit is $9,950 or $14,910.⁷
Two other programs, SLMB and QI, pay only the Part B premium. They have higher income limits.⁷
You apply through your state Medicaid office, not Medicare. Medicare.gov urges people to apply even if they are not sure they qualify. Some states count income differently.⁷

Anyone in a Medicare Savings Program also qualifies for Extra Help, which lowers Part D drug costs.^7,10

Drug maker programs and other help

Both drug makers run copay assistance lines. The Alzheimer's Association lists them:

Leqembi Copay Assistance Program: 833-453-7362⁵
Kisunla (Lilly) Copay Assistance Program: 800-545-5979⁶

Ask each program whether it can help people on Medicare, and what it can and cannot cover. Also ask the clinic whether the maker has a free-drug program for people with low income.

Other places to turn:

1-800-MEDICARE (1-800-633-4227, TTY 1-877-486-2048) answers coverage questions 24 hours a day, 7 days a week, except some federal holidays.¹⁴
SHIP counselors give free one-on-one Medicare help. They can review your plan and help you appeal a denial.¹⁴
The Alzheimer's Association Helpline, 800-272-3900, can help you find doctors and financial help.⁵
Clinical trials sometimes cover study drugs and scans. See joining a dementia clinical trial.

Steps to take before starting

Ask the doctor whether the clinic reports to a Medicare-approved registry.
Call your Medicare plan, Medigap plan or Medicaid office. Ask what you will pay for the drug, infusions, MRIs, PET scan and visits.
If you have Medicare Advantage, ask whether you need prior authorization and which centers are in network.
If money is tight, apply for a Medicare Savings Program and Extra Help through your state.
Ask the clinic's financial counselor about drug maker programs.
Keep a folder of bills, approvals and phone notes. A memory notebook can hold the medicine list and appointment dates.
If a claim is denied, call SHIP for help with an appeal.

Common questions

Is the at-home pen cheaper than IV infusions?

It depends on your coverage. The pen avoids infusion center fees and travel, but it may be paid through Part D instead of Part B. Compare what your plans would charge before choosing. MRI checks are still needed either way.^10,12

Will Medicare pay if the disease is past the mild stage?

Medicare covers these drugs only for mild cognitive impairment or mild dementia due to Alzheimer's.¹ Ask your doctor how you will decide together when to stop. See lecanemab and donanemab.

Does Medicare pay for nursing home or in-home care?

That is a separate question from paying for these drugs. Read what Medicare covers in dementia and what dementia care costs.

Where can I compare all the dementia medicines?

Our dementia medicines page lists every approved medicine and what it does.

Money worries add to a caregiver's stress. If you feel worn down, see caregiver burnout.

Sources

Medicare.gov. Monoclonal antibodies for treating early Alzheimer's disease. Centers for Medicare & Medicaid Services, 2026. Medicare.gov
Centers for Medicare & Medicaid Services. Coverage with evidence development: monoclonal antibodies directed against amyloid for the treatment of Alzheimer's disease. CMS, 2026. CMS
Medicare.gov. Medicare costs (2026). Centers for Medicare & Medicaid Services, 2026. Medicare.gov
Centers for Medicare & Medicaid Services. Transmittal R12364NCD: removal of national coverage determination for beta amyloid PET. CMS, 2023. CMS
Alzheimer's Association. Lecanemab (Leqembi). Alzheimer's Association, 2026. alz.org
Alzheimer's Association. Donanemab (Kisunla). Alzheimer's Association, 2026. alz.org
Medicare.gov. Medicare Savings Programs. Centers for Medicare & Medicaid Services, 2026. Medicare.gov
Medicare.gov. Compare Medigap plan benefits. Centers for Medicare & Medicaid Services, 2026. Medicare.gov
Medicare.gov. Compare Original Medicare and Medicare Advantage. Centers for Medicare & Medicaid Services, 2026. Medicare.gov
Medicare.gov. Costs for Medicare drug coverage. Centers for Medicare & Medicaid Services, 2026. Medicare.gov
Medicare.gov. Prescription drugs (outpatient). Centers for Medicare & Medicaid Services, 2026. Medicare.gov
U.S. Food and Drug Administration. LEQEMBI and LEQEMBI IQLIK (lecanemab-irmb) prescribing information, revised July 2026. FDA, 2026. FDA label
U.S. Food and Drug Administration. KISUNLA (donanemab-azbt) prescribing information. FDA, 2025. FDA label
Medicare.gov. Talk to someone. Centers for Medicare & Medicaid Services, 2026. Medicare.gov

Education only. This page is general information written from the sources listed. It is not medical, legal or financial advice and does not replace a doctor, therapist or lawyer who knows your situation. How we write and check pages.

Paying for new Alzheimer's drugs