Biosimilars have the potential to reduce spending and increase access to costly biologic therapies, but there are huge variations in how biosimilars were covered, compared with their reference product, by commercial health plans in the United States.

This study explores what characteristics of the biologic–indication pair are associated with the health plan’s decision to impose exclusions or step therapy restrictions for the biosimilars compared with their reference product.

Cancer treatment, pediatric population, and coverage restriction of the reference products are some of the most significant factors that are associated with biosimilar coverage decisions.