Commercial payer coverage of anti-amyloid therapy is diverging from Medicare

Medicare coverage of lecanemab and donanemab runs through a coverage-with-evidence-development pathway, with registry participation as a condition of payment. That framework has been the de facto national policy frame for the first two years of disease-modifying-therapy access, because the eligible population skews older.

The commercial-payer picture is meaningfully different. Published medical policies from major commercial plans now show:

• Prior authorization criteria that include amyloid-confirmation and APOE-genotype requirements broadly aligned with the FDA label, but with site-of-care, infusion-frequency, and reauthorization rules that vary by plan.
• Step-therapy or sequencing requirements at some plans - for example, requirements to document failure or intolerance of symptomatic therapy before initiating an antibody.
• Registry participation handled inconsistently - some plans defer to the Medicare CED registry, others have not opined.
• Coverage of plasma-biomarker testing as a triage step before PET that varies markedly between plans.

The practical effect is that for patients under 65, access depends on the specific payer's medical policy, not a single national framework. As the eligible population expands earlier into the disease course, the commercial cohort matters more - and the policy mosaic becomes more consequential.

What we are watching: whether the Medicare CED framework continues to function as a soft standard for commercial payers, or whether a meaningfully fragmented coverage landscape persists.