"This article presents a practical approach that JJ [juvenile justice] systems can take in achieving evidence-based programming that reduces recidivism. Most JJ system programs produce relatively small reductions in recidivism, on average, thus there is much room for improvement. A research-based approach to making program improvements system-wide-and with that, increase the cost effectiveness of the system itself-is presented in this article. The success of this effort, however, depends on delivery of the right service to the right youth at the right time. The OJJDP Comprehensive Strategy for Serious, Violent, and Chronic Juvenile Offenders provides the scaffolding and structured decision-making tools that can be used across entire juvenile justice systems for promoting effective matches between evidence-based services and offender treatment needs on an ongoing basis" (p. 1). Sections of this document include: introduction-what an evidence-based program is, and taking a proactive approach to program improvements; a Comprehensive Strategy for Serious, Violent, and Chronic Juvenile Offenders-the OJJDP Comprehensive Strategy, the age-crime curve, a developmental pathways model, and risk and protective factors; key administrative tools for achieving evidence-based juvenile justice systems-the right service, to the right youth, at the right time, a system of graduated sanctions/responses, and state examples of Comprehensive Strategy benefits (North Carolina and Florida); and conclusion.