This Pilot study addresses the evaluation of a novel treatment for high school students with ASD and intellectual disabilities (ID). Despite the fact that core symptoms of ASD (i.e., deficits in communication and social skills) persist well into adolescence, and students with ASD and ID experience social isolation in school and through adulthood, few studies have addressed the social-communication needs of this group. The researchers will address this critical need by piloting a peer-mediated intervention designed to improve the social-communication skills of high school students with ASD and ID and increase their social interaction with general education peers in typical high school activities. Components of the intervention consist of (a) establishing a peer support network to provide on-going feedback to general education students involved in training, (b) peer-mediated social communication training, where peers are taught to teach students with ASD and ID targeted social-communication skills, and (c) peer-assisted supports, where peers are taught to create new social opportunities and extend social interaction to other untrained peers in typical high school activities. The effects of the intervention will be evaluated by conducting 8 single-subject experiments using a multiple baseline design across students with ASD and social settings. Each replication of the design will allow us to establish the reliability and generality of findings across student characteristics (N=32) and general education peers (N=64) in four high school settings. Performance observations of social-communication skills and social interaction of students with ASD and ID with peers will occur during typically occurring activities where social behaviors are expected to occur. In addition to direct observation data, data on consumer satisfaction will be obtained by asking teachers, general education peers, and students with ASD to rate the acceptability of the intervention procedures and achieved outcomes. The results are expected to show improved targeted social-communication skills by students with ASD and ID, increased social interaction between students with ASD and ID and their general education peers (trained and untrained), and as judged by consumers, acceptable outcomes and procedures. Information gained from this study should yield novel information on how to improve and support communication and sustained social interactions among adolescents with ASD and ID in everyday settings.