Insurance Denied Alzheimer's Treatment? How to Appeal Lecanemab, Donanemab, and Memory Care Denials

Alzheimer's disease affects more than six million Americans, and for the first time in decades, FDA-approved treatments exist that can slow cognitive decline. But Medicare and private insurers have created significant coverage barriers for these new drugs — and families are fighting back. Whether your denial involves Leqembi (lecanemab), Kisunla (donanemab), a memory care facility stay, or diagnostic tests like amyloid PET scans, there are concrete steps you can take to appeal.

Why Insurers Deny Alzheimer's Treatments

The coverage landscape for newer Alzheimer's treatments is genuinely complicated, and insurers exploit that complexity. Common denial reasons include:

• CMS National Coverage Determination restrictions — Medicare's 2023 NCD for anti-amyloid antibodies initially tied coverage to participation in approved clinical studies. While CMS updated the NCD after traditional FDA approval of lecanemab in July 2023, coverage still has strict eligibility requirements
• "Not medically necessary" for the specific patient — insurers argue the patient's disease stage falls outside covered criteria (e.g., too mild or too advanced)
• Prior Authorization Denied: How to Appeal" class="auto-link">Prior authorization denied — failing to pre-certify the drug before infusion administration
• Amyloid PET scan denied — the diagnostic test confirming amyloid burden (required for eligibility) may itself be denied, blocking downstream drug coverage
• Memory care facility not covered — long-term custodial care is typically excluded from health insurance, though skilled nursing components may be coverable

Common denial codes: CO-50 (not medically necessary), CO-96 (non-covered charge), N-479 (patient not eligible under coverage conditions).

The CMS NCD Explained

Medicare's National Coverage Determination (NCD 20.35) governs coverage for monoclonal antibodies targeting amyloid for Alzheimer's. After the traditional FDA approval of lecanemab in July 2023, CMS updated coverage to allow Medicare payment for patients who meet all of the following:

• Confirmed diagnosis of mild cognitive impairment (MCI) or mild dementia due to Alzheimer's disease
• Confirmation of amyloid pathology through PET scan or CSF testing
• Treatment prescribed by a physician enrolled in a qualifying registry or study

Commercial insurers are not bound by Medicare's NCD but often use it as a baseline. Some commercial plans have issued separate coverage policies; others haven't yet — which can lead to inconsistent decisions.

Clinical Guidelines Supporting Coverage

The Alzheimer's Association, Alzheimer's Disease Neuroimaging Initiative (ADNI), and the Society for Nuclear Medicine and Molecular Imaging (SNMMI) all support appropriate use of amyloid PET for diagnosis and treatment eligibility. The Appropriate Use Criteria (AUC) published by the Alzheimer's Association provide a clinical framework for when amyloid PET is indicated.

The FDA's traditional approval of lecanemab was based on the CLARITY-AD trial, which demonstrated statistically significant slowing of cognitive and functional decline. Kisunla (donanemab) received traditional FDA approval in July 2024, supported by the TRAILBLAZER-ALZ 2 trial showing similar efficacy. These are not experimental treatments — they are approved therapies with rigorous evidence bases.

Step-by-Step Appeal Strategy

Step 1: Identify the specific denial reason. Obtain the EOB and the insurer's clinical policy for Alzheimer's drug coverage. Note the exact code and rationale.

Step 2: Confirm your clinical eligibility. Work with your neurologist to document:

• Diagnosis: ICD-10 G30.0 (Alzheimer's with early onset) or G30.9 (Alzheimer's, unspecified)
• Clinical Dementia Rating (CDR) score of 0.5–1.0 (MCI or mild dementia)
• Amyloid positivity (PET scan or CSF results)
• MMSE or MoCA score and progression over time

Step 3: Cite the FDA approval and CMS coverage update. If your insurer is denying based on "investigational" status, point to the FDA traditional approval letter and the updated CMS NCD. If a commercial insurer has no coverage policy at all, argue that the absence of a coverage exclusion means the service is covered under your plan's general medically necessary benefit.

Step 4: Challenge amyloid PET denials first. If the PET scan was denied, that denial should be appealed separately. The SNMMI AUC and Alzheimer's Association guidelines clearly support amyloid PET in patients with cognitive impairment of uncertain etiology.

Step 5: File an expedited appeal if appropriate. If the patient is currently on therapy and the insurer is threatening to discontinue coverage, request an expedited internal appeal (typically resolved within 72 hours) and a concurrent External Independent Review: Complete Guide" class="auto-link">external review.

Memory Care Facility Denials

Most health insurance plans exclude custodial long-term care. However, if a memory care facility provides skilled nursing services (wound care, medication management requiring RN oversight, rehabilitation), those components may be separately billable. Also check whether the patient has a long-term care insurance policy — this is separate from health insurance.

Supporting Evidence to Gather

• Neurologist or geriatric psychiatrist notes with CDR, MMSE, and MoCA scores
• Amyloid PET scan results and radiologist interpretation
• Neuropsychological testing results
• History of progression over 6–12 months
• FDA approval letters for lecanemab (July 2023) or donanemab (July 2024)
• Updated CMS NCD documentation
• Published CLARITY-AD or TRAILBLAZER-ALZ 2 trial summaries

Fight Back With ClaimBack

Alzheimer's coverage denials are among the most complex and emotionally exhausting battles a family can face. ClaimBack helps you build a complete, evidence-based appeal without requiring you to become an expert in insurance law or clinical guidelines.

Start your Alzheimer's treatment appeal today

Related Reading

• What Is Medical Necessity?
• Common Reasons Insurance Claims Are Denied
• How to Write an Insurance Appeal Letter