Medicare Coverage for Alzheimer's & Dementia: 2025 Guide
Alzheimer's disease affects over 6 million Americans, most of them Medicare beneficiaries. The past two years have brought historic changes to Medicare's Alzheimer's coverage — including full coverage of two new disease-modifying drugs that can slow cognitive decline. Here's what's covered, what it costs, and the significant gaps that remain.
Medicare Alzheimer's Coverage: Quick Reference
| Service | Part | Your Cost (2025) | Notes |
|---|---|---|---|
| Leqembi (lecanemab) infusions | Part B | 20% after deductible (~$5,300/year) | Requires confirmed amyloid + MCI or mild AD + CED registry |
| Kisunla (donanemab) infusions | Part B | 20% after deductible | New July 2024; stop when amyloid clears; same registry requirement |
| Amyloid PET scan | Part B | 20% after deductible | Covered for diagnosis since Oct 2023; one per patient lifetime |
| CSF (lumbar puncture) amyloid test | Part B | 20% after deductible | Alternative to PET for confirming amyloid |
| MRI monitoring (safety scans) | Part B | 20% after deductible | Required during treatment to monitor for ARIA brain swelling |
| Cognitive assessment (Annual Wellness Visit) | Part B (preventive) | $0 — free | Included in annual wellness visit; detects cognitive decline early |
| Comprehensive cognitive assessment | Part B | 20% after deductible | Detailed neuropsychological testing when medically necessary |
| Care planning visit | Part B | 20% after deductible | Separate billable visit for creating a care plan after diagnosis |
| Neurologist visits | Part B | 20% after deductible | Specialist visits for diagnosis and ongoing management |
| Home health (skilled care) | Part A/B | $0 for covered services | For homebound patients needing skilled nursing or therapy |
| Skilled nursing facility (post-hospitalization) | Part A | $0 days 1–20; $209.50/day days 21–100 | Requires 3-day qualifying hospital stay |
| Hospice (terminal stage) | Part A | $0 for most services | When prognosis is ≤6 months |
| Alzheimer's medications (Aricept, Namenda) | Part D | Usually Tier 1–2 (low cost) | Donepezil, memantine, rivastigmine covered by all Part D plans |
Leqembi and Kisunla: Medicare's Disease-Modifying Coverage
For the first time in Alzheimer's history, Medicare covers drugs that can actually slow the progression of the disease — not just treat symptoms. Here's how coverage works for both approved drugs:
Leqembi (Lecanemab) — Covered Since July 2023
- How it works: IV infusion every two weeks; removes amyloid plaques from the brain; slowed cognitive decline by 27% in clinical trials
- List price: ~$26,500/year
- Medicare cost with Part B only: 20% = ~$5,300/year (plus Part B deductible)
- Medicare cost with Medigap Plan G: ~$257/year (Part B deductible only)
Kisunla (Donanemab) — Covered Since July 2024
- How it works: Monthly IV infusion; removes amyloid plaques; treatment stops when amyloid is cleared (typically 6–12 months), reducing total cost and treatment burden
- Key distinction: The stop-when-cleared feature is unique — patients don't necessarily require years of ongoing treatment
- Coverage: Same CED registry requirement as Leqembi
Requirements for Coverage
Both drugs require the following to qualify for Medicare coverage:
- Confirmed amyloid pathology — via amyloid PET scan or CSF testing (lumbar puncture)
- Clinical stage: Mild cognitive impairment (MCI) due to Alzheimer's or mild Alzheimer's dementia — not moderate or severe
- Enrollment in a CMS-approved evidence development (CED) registry — your prescribing neurologist must be affiliated with a participating site
- No exclusionary conditions — certain genetic profiles (ApoE4 homozygotes) face higher ARIA risk; discuss with your neurologist
ARIA: The Safety Risk to Understand
Both Leqembi and Kisunla carry a risk of ARIA (Amyloid-Related Imaging Abnormalities) — brain swelling or microbleeds that can occur during treatment. ARIA is usually asymptomatic but can cause headaches, confusion, or neurological symptoms in some patients.
Medicare covers the required safety MRI scans (before treatment, and periodically during treatment) to monitor for ARIA. These monitoring scans are an essential part of the treatment protocol and are covered under Part B.
People who carry two copies of the ApoE4 gene are at significantly higher risk of ARIA. Genetic testing before starting treatment is recommended and is covered under Part B when ordered by a physician.
Amyloid PET Scans: Covered Since October 2023
Before October 2023, Medicare covered amyloid PET scans only for patients enrolled in research studies. As of October 2023, Medicare covers one amyloid PET scan per patient for Alzheimer's diagnosis — a significant access expansion. Requirements:
- Ordered by a physician evaluating cognitive impairment
- The patient has confirmed cognitive symptoms that haven't been explained by other diagnoses
- Results will change management or improve care planning
- The ordering physician must follow up with the patient to discuss results
- Coverage is limited to one scan per patient lifetime under standard Medicare (additional scans may be covered in certain research or monitoring contexts)
What Medicare Does NOT Cover for Alzheimer's
- Memory care assisted living: Memory care facilities and assisted living are not covered by Medicare, regardless of the level of dementia
- Custodial nursing home care (ongoing): Medicare covers only the first 100 days in a skilled nursing facility after a qualifying hospital stay — not long-term custodial care
- Home health aide (non-skilled): A home health aide helping with bathing, dressing, and safety supervision is not covered unless skilled care is also being provided simultaneously
- Adult day programs: Not covered under Original Medicare (some Medicare Advantage plans may offer partial coverage)
- Caregiver respite (extended): Limited respite care is covered under hospice; no ongoing caregiver respite benefit outside hospice
- Experimental treatments: Treatments not yet FDA-approved or outside approved clinical trials
Long-Term Care Planning for Alzheimer's Families
The average lifetime cost of Alzheimer's care is estimated at $350,000+, and Medicare covers only a fraction of that. Planning options include:
- Long-term care insurance — ideally purchased before symptoms appear; covers custodial care in facilities and at home
- Medicaid — covers ongoing nursing home care after assets are spent down to state limits; complex eligibility rules; 60-month look-back period for asset transfers
- Veterans benefits — Aid and Attendance pension for qualifying veterans may cover in-home or facility care
- Medigap Plan G — covers the 20% Part B coinsurance for disease-modifying drug infusions and monitoring MRIs, reducing annual drug treatment costs from ~$5,300 to ~$257
Frequently Asked Questions
Yes, with conditions. Medicare Part B covers Leqembi (lecanemab) infusions for patients with confirmed amyloid pathology (via PET scan or CSF test) and MCI or mild Alzheimer's dementia who enroll in a CMS-approved evidence development registry. The drug costs ~$26,500/year; Medicare pays 80% after the Part B deductible. Medigap Plan G covers the remaining 20%, reducing your cost to ~$257/year (the Part B deductible).
Kisunla (donanemab) is the second FDA-approved Alzheimer's disease-modifying therapy. It received traditional FDA approval in July 2024 and Medicare coverage under the same CED framework as Leqembi. Kisunla is notable because treatment can stop once amyloid plaques are cleared — which typically occurs within 6–12 months — potentially limiting total treatment duration and cost. The same eligibility requirements apply as for Leqembi.
No. Medicare does not cover memory care facilities, assisted living facilities, or ongoing custodial nursing home care for Alzheimer's or dementia patients. Medicare covers skilled nursing for up to 100 days after a qualifying hospital stay, and home health when skilled care is being provided. Long-term custodial care must be paid out of pocket or through long-term care insurance, until Medicaid eligibility is established.
Yes, as of October 2023. Medicare covers one amyloid PET scan per patient lifetime for Alzheimer's diagnosis when ordered by a physician and medically necessary. The scan costs ~$3,000–$6,000; Medicare pays 80% after the Part B deductible. This coverage replaced the previous requirement that patients participate in a research study to access this diagnostic tool.