Purpose. This funding opportunity announcement (FOA) encourages research grant applications to support research designed to elucidate the etiology, epidemiology, diagnosis, treatment, and optimal means of service delivery in relation to autism spectrum disorders (ASD). Basic, clinical, and applied studies are encouraged. This FOA is intended to support the broad research goals of the Strategic Plan for ASD Research (http://iacc.hhs.gov/reports/2009/iacc-strategic-plan-for-autism-spectrum-disorder-research-jan26.shtml).