The use of Infant and Early Childhood Mental Health Consultation (IECMHC) has grown dramatically over the past decade to support the skills and reflective capacity of adults who care for infants and young children birth to kindergarten entry. Research to date has shown promise for IECMHC to support children's social and emotional development. However, there is a gap in the published research that articulates how fidelity to a specific statewide IECMHC model impacts desired outcomes for adult caregivers or the infants and children they serve. This article, which articulates the process that Colorado used to develop its own IECMHC model, is the first step in filling this gap in the research. The step-by-step approach to model development can be used by other states undertaking similar efforts to create models that are geared toward a variety of settings, such as early education, home visitation, or health care. Colorado is beginning statewide implementation of the model that resulted from this process and will soon start evaluating the fidelity of that implementation. This process creates the groundwork for ultimately tying implementation of an articulated IECMHC model to outcomes for adults and the infants and children they care for.