U.S. policymakers are making greater use of findings from systematic reviews, the principal product of the discipline of research synthesis. This paper summarizes the methodology and availability of systematic reviews and the brief history of their introduction to policymakers in the public and private sectors and health professionals in the United States. Then, as a case study, the paper describes how officials in a consortium of states are using systematic reviews to inform decisions about coverage for pharmaceuticals. Finally, it explores the prospects for wider use of systematic reviews by policymakers.