Antibody Tests for Neurologic Diseases (CPB 0340, reviewed 2026-07-08)

IMMEDIATELY (effective 2026-07-08): Billing and clinical teams must implement the following: (1) Billing team: Update denial rules and billing system software to flag antibody test claims that lack required clinical documentation (symptoms, prior test results, imaging findings, or electrophysiology studies). (2) Providers and clinical staff: Ensure all antibody test orders include documented medical necessity meeting Aetna's specific criteria for the suspected condition (e.g., for AChR testing: document fluctuating weakness, ptosis, diplopia, bulbar or generalized weakness symptoms AND confirm testing is initial diagnostic evaluation AND confirm RIA or CBA methodology). (3) All staff: DENY or request resubmission for: screening tests in asymptomatic patients, antibody testing without documented clinical features of encephalitis, isolated VGKC testing without LGI1/CASPR2 specificity, repeat MOG testing for follow-up monitoring, and routine anti-neuronal antibody testing for early childhood epilepsy without autoimmune encephalitis features. (4) Coding/Billing: Route all antibody test requests through medical necessity verification before submission to Aetna. (5) Documentation: Add a checklist to encounter templates requiring providers to document: patient symptoms, prior test results, imaging/study findings, and clinical suspicion rationale. CONSEQUENCE: Claims submitted without required documentation or for non-covered scenarios (e.g., screening, repeat monitoring) will be denied by Aetna. No specific CPT/HCPCS codes are listed in this policy; verify code assignment separately with Aetna's billing guidance.