For six years, under the informal leadership of a few professionals committed to fostering the healthy social and emotional development of infants and young children in Tennessee, a group of passionate individuals and agencies came together on a bimonthlly and subsequently quarterly basis for the purpose of building relationships, identifying existing resources and opportunities, and beginning to identify what is needed to address the mental health needs of the birth through age 5 population. From the initial meeting of 25 or so individuals, the attendance and agency representation steadily grew and the group’s identity as a valuable initiative was established. In this presentation, the expansion of this informal grassroots initiative into a formal non-profit corporation receiving funding from the Tennessee Department of Health to support developing the capacity and quality of the early childhood workforce will be described. The presenter also will describe the current work of the Association of Infant Mental Health in Tennessee (AIMHiTN), including the implementation of the Infant Mental Health (IMH) Endorsement® for Culturally Sensitive, Relationship-Focused Practice Promoting Infant Mental Health (IMH-E®), an internationally recognized credential.