In collaboration with program developers, Child Trends, and with support from the FPG Child Development Institute, the National Implementation Research Network conducted an implementation and pre-post outcome study of the online associate's degree program for infant and toddler teachers developed by the University of Cincinnati/Zero to Three/WestEd partnership, called the Mentor Infant and Toddler Teacher (MITT) Initiative. The primary purpose of this collaborative project is to design and deliver a comprehensive professional development system of support for infant and toddler teachers, anchored in an online associate's degree program for English- and Spanish-speaking professionals serving infants and toddlers.