We evaluated the effectiveness of a statewide Medicaid program providing in-home Early Intensive Behavioral Intervention services to young children with Autism Spectrum Disorder living in a rural southern state. Program effectiveness was assessed via the Assessment of Basic Language and Learning Skills-Revised (ABLLS-R). A multi-level growth model was used to show significant variation among children's initial ABLLS-R scores and their growth trajectories. Hispanic children tended to have lower initial scores but demonstrated similar growth compared to their non-Hispanic peers. Children who were older at initial start in the program appeared to have higher initial composite scores and higher growth trajectories. Children in more populous counties had higher initial scores but grew at similar rates to children in more rural counties.