The large number of children served combined with the richness of data collected by Head Start agencies piqued the interest of the Missouri Coordinating Board for Early Childhood (CBEC). When Federal funding opportunities were presented in 2011 through the American Recovery and Reinvestment Act, CBEC, through the state Department of Social Services (DSS), was awarded a two-year grant and established a contract entitled "Supporting Head Start Participation in Missouri's Early Childhood and P-20 Longitudinal Data Systems." This policy brief details Missouri's progress toward inclusion of Head Start data in the state's longitudinal data system and concludes with implications for policy and process. (author abstract)