OBJECTIVES: US health plans have been slow to adopt newer biosimilar (BS) drugs partly due to uncertainties surrounding their safety, efficacy and economic superiority. This study aims to collect evidence of economic value of four new biosimilars that have been FDA-approved for sale so far to provide information that might aid formulary adoption and uptake by health plan decision makers (HPDMs). METHODS:  A systematic review of pharmacoeconomic studies of four USFDA-approved biosimilars to date (filgrastim, infliximab, etanercept, adalimumab) from PubMed, Embase, and SciDirect databases. Eligible studies included cost-based comparative evaluations of a biosimilar product vs. another biologic, an originator product, or a qualified reference product. Empirical and review studies documenting traditional HEOR results, findings of comparative effectiveness, budget impact analyses (BIA) and resource use projections were drawn from multiple literature databases for final review RESULTS: We identified 44 studies (15 peer reviewed articles and 29 meeting abstracts) that met the eligibility criteria. Nearly all the studies were either simulated models with cost projections or retrospective cost analyses (>90%) with only three real-world utilization studies; only four were US-based studies. BIAs constituted a majority (>75%) and more than half involved multi-national comparisons in EU. QALYs, incremental costs, and projected savings to cover additional lives were the most common outcome measures. Price discounts modeled varied from 20% to as high as 75%, and savings generated were substantial to significant in most cases. CONCLUSIONS:  US studies demonstrating the value of BS are extremely rare, but the international experience with these products shows strong cost advantages. Market uptake rates and acquisition cost discounts drive savings in most cases and savings are sensitive to jurisdictional variations, interchangeability parameters and clinical factors .Scarcity of real-world performance data in the USA, and the difficulty of using European commercial experience for US adoption and forecasting make immediate BS acceptance challenging.