U.S. health plan coverage of Neuromuscular Disease Therapies: An assessment of policy availability and restrictions.

backgroundHealth plan policies managing neuromuscular disease (NMD) therapies may impose burdensome requirements on patients and providers. While prior research has explored payer restrictions for rare NMD treatments, limited evidence exists on policies specifically governing therapy initiation and reauthorization.

objectivesTo examine initial and reauthorization coverage policies for therapies targeting five NMDs-Duchenne muscular dystrophy, amyotrophic lateral sclerosis, spinal muscular atrophy, generalized myasthenia gravis, and Lambert-Eaton myasthenic syndrome-across all U.S. state Medicaid programs and leading commercial health plans.

methodsWe constructed a database of coverage decisions issued by 50 states and DC Medicaid programs and 35 major commercial insurers, including both fee-for-service and managed care organizations. We analyzed (1) policy availability and coverage frequency, (2) initial coverage requirements (e.g., subgroup restrictions, step therapy, prescriber type), (3) reauthorization criteria, and (4) approval durations.

resultsOf 1204 potential decisions, 908 (75%) had publicly available policies. Of these, 558 (46%) included reauthorization criteria. Among covered therapies, 96% imposed restrictions beyond FDA label indications. Requirements varied by payer type, NMD, and therapy. Average approval durations were 6 months for initial coverage and 10 months for reauthorization.

conclusionsMany plans lacked publicly accessible policies, and most covered therapies were subject to restrictive requirements. These barriers-such as step therapy, narrow prescriber criteria, and short approval periods-may delay treatment and disrupt care continuity. Findings underscore the need for greater transparency and reform in prior authorization and pharmacy benefit design to support timely access to NMD therapies.