In This Section

Autism Prevalence


What is the Prevalence of Autism Spectrum Disorder (ASD)?

The word prevalence means how common something (in this case, Autism Spectrum Disorder or "ASD") is in the general population. In April 2018, the prevalence of ASD was reported by the Centers for Disease Control and Prevention to be 1 in 59 children, with a male to female ratio of 4:1. That means 1 in 37 males and 1 in 151 females have symptoms consistent with ASD. This is increased from the last reported prevalence estimates published in 2014 (when the rate was estimated to be 1 in 68 children), 2012 (when the rate was estimated to be 1 in 88 children), 2006 (when the rate was estimated to be 1 in 110), and from 2004 (when the rate was estimated to be 1 in 150).

How Were These Prevalence Studies Done?

Congress funds the Centers for Disease Control to monitor the rate of ASD across the country. States submit applications to join the CDC Autism and Developmental Disabilities Monitoring Network (ADDM) and are chosen based on their ability to collect high quality data from as complete a geographical region as possible. All data must be collected in a similar manner so the results can be combined across all the sites within the ADDM network. ADDM studied the health and educational records of 8 year old children and compared the results to DSM-IV-TR (Diagnostic and Statistical Manual of Mental Disorders, 4th edition, Text Revised) and/or DSM – 5 (Diagnostic Statistical Manual of Mental Disorders, 5th edition) diagnostic criteria to determine if the child met criteria for ASD for the 2018 prevalence estimates. Eight year olds were chosen because it is a relatively young age, but it is old enough to capture the overwhelming majority of children with autism and Asperger Syndrome. The current ADDM Network sites include: Arizona, Arkansas, Colorado, Georgia, Maryland, Minnesota, Missouri, New Jersey, North Carolina, Tennessee, and Wisconsin. In the past, Pennsylvania has been a site as well. Every few years the ADDM network updates their findings, so that people can better understand the current rates and changes from previous reports. The current prevalence estimates are based on records from 2014.

What Have the Studies Told Us?

The estimated prevalence of ASD increased approximately 30% from 2012 to 2013, 23% from 2006 to 2008, and 73% from 2002 to 2008. These studies showed us that over time, children on the autism spectrum are being identified at younger and younger ages. In the most recent report published in 2018, most children were diagnosed with ASD by age 4 years. Many fewer children were identified as having both autism and an intellectual disability (69% did not have an intellectual disability). In addition, more Black and Hispanic children are now being identified compared to earlier years.

Why is it Important to Know What the Prevalence of ASD is?

If we know and can predict the number of individuals on the autism spectrum, communities can prepare for the future and have services and supports available for those who will need them.

Additional Resources

The Center for Autism Research and The Children's Hospital of Philadelphia do not endorse or recommend any specific person or organization or form of treatment. The information included within the CAR Autism Roadmap™ and CAR Resource Directory™ should not be considered medical advice and should serve only as a guide to resources publicly and privately available. Choosing a treatment, course of action, and/or a resource is a personal decision, which should take into account each individual's and family's particular circumstances.