Autism spectrum disorder (ASD) can be diagnosed as early as 18 months of age. State Early Intervention (EI) programs under Part C of the Individuals with Disabilities Education Act (IDEA) are serving increasing numbers of children with ASD; however, little is known about outcomes of these services. This study evaluated the impact of EI for toddlers with ASD (n = 193) and other disabilities (n = 129) and their families, using measures that included federal Part C outcome indicators. Children with ASD showed reduced maladaptive behaviors and improved social and communication skills on the PDD Behavior Inventory; some also made progress on the Part C child outcome indicators. Families of children with ASD reported that EI helped them achieve many outcomes identified as important to families participating in EI. Results provide a rich description of outcomes experienced by children with ASD and their families in one of the largest EI programs in the United States. Implications for results-driven accountability and future research are discussed.