Recent CDC data on the prevalence of autism in the United States identified 1 in 68 children as having autism spectrum disorder (ASD), and it has been estimated that more than 3.5 million people in the United States live with ASD. OT practitioners work with individuals with ASD and their families in a variety of practice settings across the lifespan, often beginning in early childhood and including multiple transitions into adulthood. This Practice Guideline provides an overview of the evidence for occupational therapy to assist people with autism in achieving health, well-being, and participation in life through engagement in occupations. It includes a description of the occupational therapy process for this population, defining the domain and describing interventions that occur within acceptable practice. Extensive attention is given to sensory, psychosocial, and family issues. Appendixes include selected CPT codes and searchable Evidence Tables for ease of use.