Autism spectrum disorder (ASD), a common neurodevelopmental disability, typically can be diagnosed within the first 3 years of life, usually by age 24 months. The median age of diagnosis in the United States is 4.5 years, which is substantially later than when symptoms emerge.1 Despite increasing public awareness, only 43% of children with ASD receive a comprehensive developmental evaluation by age 3 years.1 Timely detection facilitates access to appropriate developmental and behavioral intervention that, when begun soon after symptom onset, can substantially improve outcomes and reduce parents’ stress.