This large national study will identify the impact of state level autism-related policies on the publicly funded healthcare utilization of children with autism spectrum disorders (ASD). The primary aims of the study are to conduct an intensive examination of state policies and practices that may affect Medicaid-reimbursed healthcare delivery to children with ASD, to provide accurate national and state-level estimates of publicly-funded healthcare utilization among children with ASD, and to examine the relative contribution of demographic, clinical, and system-of-care characteristics on the types, intensity, and patterns of related service use. This study will set the stage for future studies in which service utilization data from other systems and primary data about families' experiences and outcomes are linked to data on healthcare. The study also will provide a baseline against which to measure the effects of future system-level interventions. Finally, the results will provide evidence for a conceptual framework for understanding how states address the needs of children with chronic disabilities in which the best course of treatment and expected outcomes are uncertain.