Recent prevalence rates for autism spectrum disorders (ASDs) are now estimated at about 1 in 110 children in the U.S. Increases in public awareness and research funding in response to the growing numbers of children and adults with this disorder have led to numerous important scientific advances over the last several years. Nevertheless, because ASD remains a diagnosis that is defined completely on the basis of behavior, diagnostic assessment is both complex and expensive. Appropriate interventions and services are also multi-faceted and costly, and because of the pervasive nature of the disorder, are often required in some form across the lifespan. In the absence of standard societal mechanisms to pay for appropriate assessment and treatment, families must personally shoulder many of the costs associated with securing appropriate services for their children. This "Social Policy" Report summarizes selected recent studies on diagnosis, prevalence, and intervention, and discusses strategies for designing social policies to help improve the outcomes and independence of children and adults with ASDs. (Contains 2 tables and 1 figure.) [Commentaries from Geraldine Dawson, David Mandell, and Fred R. Volkmar are included, and are individually referenced.]