A growing literature highlights established and developing approaches to infant mental health assessment and treatment. Like other evidence-based and theory-based interventions, real world application of these approaches requires an understanding of the theoretical and empirical foundations of infant mental health as well as consideration of cultural, systemic, and logistical factors. In this article, the authors present models of universal and targeted interventions in infant mental health, with attention to the adaptations used to apply evidence-based practice in real world settings.