Why do many social programs have such a poor track record? What can we do to maximize a program's chance of success? If a program shows promise, how can we scale it up? To answer these questions confronting policymakers, and to ensure that strong programs are designed, developed, implemented, and taken to scale, appropriate evaluation approaches must be used throughout a program's life cycle. In The Oxford Handbook on Program Design and Implementation Evaluation, Dr. Anu Rangarajan surfaces insights and expertise from a team of eminent scholars to create a comprehensive and actionable toolbox of evaluation methodologies that can be used to examine social programs throughout their life cycle. The methodologies presented in the Handbook describe how to conduct developmental evaluations, perform rapid-cycle evaluations, employ implementation science concepts, assess program effectiveness in the absence of a true counterfactual, measure cost-effectiveness, scale up promising interventions, and assess systems change. Incorporating these approaches at every stage of a program's life cycle will maximize its chances of success; doing so consistently across social programs will help improve their impact overall. This Handbook is an action-oriented primary resource for social researchers, faculty and students, program practitioners, policy analysts, and funders of social programs and evaluations. By providing real-world examples of each approach alongside methodological guidance, and by highlighting challenges and lessons learned, the Handbook is invaluable to novices and seasoned professionals alike.