Medicare and Alzheimer's Infusion Drugs (Leqembi, Kisunla): Billing Basics for Families

Medicare Part B may cover FDA-approved Alzheimer's drugs that target beta-amyloid plaques, like Leqembi (lecanemab) and Kisunla (donanemab), for people with mild cognitive impairment or mild dementia due to Alzheimer's. Medicare.gov says coverage requires the doctor to collect information for a qualifying study or registry. After the Part B deductible, you pay 20% of the Medicare-approved amount, and scans and tests can add more.

Who qualifies for coverage?

Medicare.gov says your provider must:

1. Confirm you have beta-amyloid plaques consistent with Alzheimer's disease, and
2. Diagnose you with mild cognitive impairment due to Alzheimer's or mild dementia due to Alzheimer's.

These drugs are for early Alzheimer's. Medicare.gov notes they may slow or delay symptoms, but they don't cure or reverse the disease.

A full memory evaluation can be a first step. See cognitive assessment visits.

What is the registry requirement?

Medicare covers these drugs under a policy CMS calls Coverage with Evidence Development. Medicare.gov says your doctor or other provider must collect evidence about how well the drugs work for a qualifying study or registry.

CMS's page links to its National Patient Registry. It says prescribing clinicians or their staff submit data at the first treatment and every six months for up to 24 months.

For families, this happens mostly between the doctor and CMS. But it matters: if the doctor isn't taking part in a qualifying registry or study, Medicare may not cover the drug.

What to ask the doctor's office:

"Is the doctor submitting data to a CMS-approved registry or study for this drug, so Medicare will cover it?"

What will we pay?

Medicare.gov says that after you meet the Part B deductible, you pay 20% of the Medicare-approved amount for the drug. CMS lists the 2026 Part B deductible at $283.

Because these drugs are given on a regular schedule, 20% of each infusion can add up. What helps:

• Medigap plans that pay the Part B coinsurance can cover most or all of it. See what Medigap plans pay.
• Medicaid or a Medicare Savings Program may help if income and savings are limited. See Medicare Savings Programs.
• Medicare Advantage plans set their own cost sharing and may require prior authorization. Ask your plan. See Medicare Advantage prior authorization.

If you don't meet Part B's criteria, Medicare.gov says your Part D plan might cover the drug. Contact the plan.

What other bills come with treatment?

Medicare.gov says you may need scans and tests before or during treatment that might add to your costs. Medicare.gov also says the drug is given through a vein in a provider's office or other outpatient setting.

So a family might see bills for:

• The drug itself.
• The infusion visit or administration.
• Brain scans, like MRIs, before and during treatment.
• Tests to confirm amyloid plaques.
• Doctor visits to check how treatment is going.
• A facility fee if infusions are in a hospital outpatient department.

Each can carry its own 20%. For how Part B drug bills work in general, see Part B drug and infusion bills.

How do we check the bills?

Keep a simple log:

• Date of each infusion.
• Date and type of each scan.
• Each bill you get, and its matching line on your Medicare Summary Notice (MSN).

Then check:

• Is each infusion billed once? See duplicate charges on a medical bill.
• Does your share match the MSN? It should be at or below "maximum you may be billed."
• Did Medigap or other coverage get the claim?

What to say if a bill doesn't match:

"I'm looking at a bill for [drug / scan] on [date]. My MSN shows the most I may be billed is $[amount], but the bill says $[amount]. Can you check whether it was sent to my Medigap plan, and correct the balance?"

What if Medicare denies a claim?

Look at the denial reason on the MSN. If it relates to eligibility or the registry, ask the doctor's office first. They may need to send more records. You can appeal. See how to appeal a Medicare denial.

What if I'm helping a parent?

Treatment involves many visits and bills. Ask to be the contact for billing, with your parent's OK. See how to get permission to talk to Medicare for a parent and managing a parent's medical bills.

Before treatment starts, ask the office for an estimate of your share for the drug, infusions, and scans over the first few months.

Frequently asked questions

Does Medicare cover Leqembi and Kisunla?

Part B may cover them if you have confirmed amyloid plaques and mild cognitive impairment or mild dementia due to Alzheimer's, and your doctor takes part in a qualifying study or registry.

How much will I pay for an Alzheimer's infusion with Medicare?

After the Part B deductible ($283 in 2026), you pay 20% of the Medicare-approved amount. Medigap may cover that.

Why are there so many bills?

The drug, the infusion, scans, tests, and doctor visits can each be billed separately.

What is the registry requirement?

Medicare requires the doctor to collect data for a CMS-approved study or registry for these drugs to be covered.

Track treatment bills month by month

Bill Review Coach is a monthly medical bill review service for seniors and their families. Upload your first bill free, no card needed. Family helpers can join free. Snap a photo of each bill and your Medicare notice, and you'll get back a plain-English summary of what matches, what looks off, and what to say. Refer a friend and you both get a free month once they join the paid plan. You make the calls and write the emails; we help you know what to say.