This study examined the utilization rate of behavioral health services by children with autism spectrum disorders (ASD) over a 6-year period and compared this rate to the expected number of children with ASD in TennCare, Tennessee's managed care Medicaid program. Analysis of TennCare patient data found the rate at which children with ASD received a behavioral health service was 0.24/1000 in Fiscal Year 1995 and 0.57/1000 in Fiscal Year 2000. It notes that, although the rate doubled over time, so did the number of children who participated in TennCare. The paper concludes that the low rate of service use confirms the need for research on service use patterns such as access, type, duration, and continuity of services for children with ASD and the impact of Medicaid-managed care on child and family outcomes. An unexpected finding was the relatively low rate of children reported with ASD receiving services from TennCare. (DB)