The U.S. Global Change Research Act of 1990 was signed into law and established a program to “most effectively advance scientific understanding of global change and provide usable information on which to base policy decisions relating to global change.” What exactly constitutes “usable” information was never defined in the legislation, and it was thus left to managers to interpret this element as the program was implemented. Early critiques of the program suggested that the program had failed to provide usable information. Based on work of the past decade, however, we are now able to reflect on specific programs in climate science that have been conducted following a deliberately different model to provide usable information to decision makers for shorter and long-term decision making at the regional scale. The focus of our work is to review this experience from the published literature to examine how “usable science” was defined, from whose perspective, and how societal goals and outcomes factored in to the definition process. As a part of this work we will explore how the decision context is constructed, how potential users of knowledge are identified, and how institutional constraints affect whether science is usable. In defining whether knowledge is “usable,” we suggest that one of the first questions to ask is “usable to whom?,” coupled with a clear discussion of expected outcomes from use of the scientific knowledge. Finally we discuss issues of equity and unintended consequences in the provision of scientific knowledge. We review literature primarily from the seasonal to interannual climate science arena but also draw on other examples from the literature of research conducted to inform decision making. We hope that our synthesis will provide new insight on lessons learned thus far, as well as spark discussion among those interested in leading or designing future programs aiming to create “usable information.”