There is a significant increase in the prevalence of autism and autism spectrum disorders (ASD) in children with estimates now reaching 1 in 110 children in the United States. Families report difficulties in finding services for their young and adult children. Many adults with ASD receive services and supports through state intellectual and developmental disabilities (IDD) adult service systems. This study presents descriptive data on a random sample of 12,382 individual users of adult IDD services from 25 states that included 1002 individuals with an autism diagnosis (8.1%). Data are provided on demographic characteristics, diagnoses, communication and relationship status for adults with autism/ASD and a comparison of these findings for IDD service users who have other diagnoses. (Contains 4 tables and 2 figures.)