The prevalence of autism spectrum disorder (ASD) has varied over time and across the United States. This variability is likely related to external factors, such as regional differences in ASD-related resources. The study reported on here examined the links between ASD prevalence as measured by Individuals with Disabilities Education Act (IDEA) Part B child count data and four aspects of state infrastructure (health care and insurance policies, clinical resources, research infrastructure, and awareness-raising individuals/organizations). This study also investigated whether these constructs varied by geographical region. The data for this study were abstracted from publicly available databases. Information on state infrastructure was gathered from high-quality reports, resource guides, certificant registries, and databases. More comprehensive ASD-relevant insurance and health care policies, more clinical resources, and greater research infrastructure were associated with higher ASD state prevalence rates as measured by the IDEA Part B child count data. Prevalence of ASD was higher in eastern U.S. states compared with southern U.S. states, but state-level ASD resources did not statistically significantly differ across geographic regions. Implications for research, practice, and policy are discussed.