Each year, the IACC releases a list of scientific advances that represent significant progress in the field. The 2017 Summary of Advances provides short, plain language summaries of the top research breakthroughs selected by the IACC from a pool of research articles nominated by the members. The 20 studies selected for 2017 have provided new insight into potential biomarkers to predict risk of autism spectrum disorder (ASD), developmental trajectories of children with ASD, and the impact of various prenatal exposures on ASD risk. The advances also include studies that investigated treatments and interventions for both ASD and co-occurring conditions, the impact of policy changes on ASD health care spending, patterns of injury mortality, and prevalence differences across demographic groups. Articles in the IACC Summary of Advances are grouped according to the topics represented by the seven questions of the 2016-2017 IACC Strategic Plan for ASD. Citations for the articles selected for the Summary of Advances, as well as a complete listing of those nominated, are included at the end of the document.