Biosimilars have the potential for saving billions of dollars for US health systems, payers, and patients, but only 3 biosimilars have been marketed, with modest savings seen to date. In this review published in the Journal of Medical Economics, the authors explain that until multiple biosimilars are available for an individual reference drug—which has just occurred in the infliximab market—savings obtained will remain around 15%. This will restrain payers from creating biosimilar tiers (with less cost sharing), as well as threaten the viability of biosimilar manufacturers in this country.