Understanding Autism Spectrum Disorder

A comprehensive resource for educators, families, and support professionals — grounded in research and built with care.

Autism Spectrum Disorder (ASD) is a neurodevelopmental condition characterized by persistent deficits in social communication and social interaction across multiple contexts, as well as restricted, repetitive patterns of behavior, interests, or activities. These symptoms are present from early developmental periods and cause clinically significant impairment in social, occupational, or other important areas of functioning.

American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA: American Psychiatric Publishing.

Autism Spectrum Disorder — Current Statistics (2025)

  • 1 in 31 children in the U.S. are diagnosed with ASD by age 8 — up from 1 in 36 in 2023 (CDC ADDM Network, 2025) Autism Parenting Magazine
  • ASD is over 3× more common in boys than girls; boys are diagnosed at a rate of 49.2 per 1,000 vs. 14.3 per 1,000 for girls (CDC ADDM, 2025) CDC
  • ~40% of children with ASD also have an intellectual disability (IQ ≤ 70) — up from the previously cited 31% (CDC ADDM, 2025) CDC
  • $2.4M estimated lifetime cost of supporting a person with ASD + intellectual disability; $1.4M for those without ID (Buescher et al., JAMA Pediatrics)
  • 47 months is the national median age of ASD diagnosis — with only half of children diagnosed by age 3 (CDC ADDM, 2025) Pathfinders for Autism
  • 64–91% heritability rate based on twin studies, with broader family studies estimating around 80–90% (meta-analysis; confirmed by Martini et al., 2024) Wikipedia
  • Children born in 2018 were nearly 1.7× more likely to be diagnosed by age 48 months than those born just four years earlier (CDC ADDM, 2025) MAC Midwest
  • Highest ASD rates by race/ethnicity: Asian/Pacific Islander (1 in 26), American Indian/Alaska Native (1 in 27), and Black children (1 in 27) — compared to White children (1 in 36) (CDC ADDM, 2025) Pathfinders for Autism
  • ASD prevalence among boys is 1 in 20; in California it is as high as 1 in 12.5 (CDC ADDM, 2025) Autism Parenting Magazine