Program theory reconstruction is an often-overlooked aspect of social intervention research. In this paper, we argue that intervention research benefits if the research design is informed by the specific intervention's program theory (i.e., the idea of how the intervention is supposed to lead to the intended outcomes). The purpose of this paper is to offer a comprehensive and accessible guide to program theory reconstruction in research on social interventions and to provide arguments as to how program theory reconstruction can be used to benefit intervention studies. First, we summarize what program theory is and its role in intervention research. Second, we provide a direct ?how-to? for researchers, practitioners, and students who may be unfamiliar with the methods of program theory reconstruction but are interested in undertaking a program theory reconstruction. Finally, we conclude with how program theory reconstruction can benefit intervention research.