Biosimilars represent one potential solution to the high prices of biologics and may expand access to these effective yet costly treatments. The US Food and Drug Administration (FDA) describes biosimilars as biologic products that have “no clinically meaningful differences between [the biosimilar] and the reference product in terms of safety, purity, and potency.”1 In contrast to small–molecule generic drugs, biosimilars are complex molecules produced in living cells that subsequently undergo posttranslational modifications. These unique structural changes relative to their reference products may lead to less predictable safety and efficacy.2 As such, regulations on biosimilar approvals are significantly stricter than with generics, requiring extensive in vitro, in vivo animal, and human clinical studies. Therefore, while the low barrier to entry seen with generics fosters market competition and discounts on prices approaching 80% to 90%, price discounts for biosimilars relative to their brand name biologics are expected in the range of 20% to 40%.3