This study used propensity score techniques on data from the National Longitudinal Transition Study-2 to assess the causal relationship between speech and behavior-based support services and rates of social communication among high school students with Autism Spectrum Disorder (ASD). Findings indicate that receptive language problems were significantly reduced among students with ASD who received behavioral and family support services. These results provide practitioners, advocates, and families with a clearer national picture of the linkage between behavior-based services and their impact on social communication outcomes, and illustrate the importance of these services in improving the social communication skills of adolescents with ASD.