Early, trauma-focused intervention development has emphasized unidirectional trajectories that begin with basic research and efficacy trials followed later by effectiveness and dissemination studies. In this article, the authors present methods derived from social and clinical epidemiology that constitute foundational research in the development of early trauma-focused intervention. They also describe how population-based practice research may serve to feed back and inform what has been conceptualized as earlier stages of intervention development such as efficacy trials. Examples of relevant epidemiologic research methods are presented to illustrate these points. The authors posit that the continued application of population-based methods may produce treatments that can be feasibly applied to the unique patient, provider, organizational, and community contexts relevant to early interventions for survivors of trauma.