Autism Rates by State 2025

Autism, or autism spectrum disorder (ASD), is a developmental disability characterized by challenges with social skills, speech, non-verbal communication, and repetitive behaviors. Typically, there is nothing visually that sets people with ASD apart from anyone else; however, people with ASD may learn, interact, behave, and communicate in ways that are different from most people.

The reason that autism is also called autism spectrum disorder is that the disability occurs on a spectrum, with the range and severity of symptoms varying widely. Children or adults with autism might:

• Avoid contact and want to be alone
• Have trouble understanding other people’s emotions or talking about their own feelings
• Be unaware when people talk to them
• Have trouble expressing their needs using typical words
• Have trouble adapting when a routine changes
• Not look at objects when another person points to them
• Have unusual reactions to the way things smell, taste, feel, look, or sound

Diagnosing autism can be difficult since there is no medical test that can determine the disorder. Autism, however, can sometimes be detected at 18 months or younger and by age two, an experienced professional can usually provide a reliable diagnosis. Early recognition, as well as behavioral, educational, and family therapies, may reduce symptoms and support development and learning.

ASD occurs in all racial, ethnic, and socioeconomic groups. ASD is four times more common among boys than among girls. There are several environmental, biological, and genetic factors that make a child more likely to have an ASD, including:

• Children born to older parents
• Children with a sibling who has ASD
• The prescription drugs valproic acid and thalidomide have been linked with a higher risk of ASD if taken during pregnancy
• ASD tends to occur more often in people who have certain genetic or chromosomal conditions.

According to the CDC’s Autism and Developmental Disabilities Monitoring (ADDM) Network, about 1 in 59 children has been identified with ASD.

The estimated state-level prevalence of autistic adults varies from about 1.97% in Louisiana to 2.42% in Massachusetts. South Carolina is the only other state with a low prevalence below 2%. Other states with a high prevalence above 2.3% are New Jersey, Illinois, Pennsylvania, Minnesota, California, Connecticut, and Virginia.