In 2006, long-term forecasts indicated that Washington faced the need to construct several new prisons in the following two decades. Since new prisons are costly, the legislature directed the Institute to project whether there are “evidence-based” options that can reduce the future need for prison beds, save money for state and local taxpayers, and contribute to lower crime rates. As part of a systematic review of the research evidence, we found and analyzed 545 comparison-group evaluations of adult corrections, juvenile corrections, and prevention programs to determine what works, if anything, to reduce crime. We then estimated the benefits and costs of many of these evidence-based options and found that some evidence-based programs produce favorable returns on investment. This paper presents our findings and describes our meta-analytic and economic methods.