Autism Prevalence

December 02, 2021


The US Centers for Disease Control and Prevention (CDC) tracks autism prevalence to better understand the scope and impact autism has upon children, families, and communities.  Service providers and organizations use these findings to prepare to meet the support needs of the families they serve.  The following links to the CDC Prevalence and Characteristics of Autism Spectrum Disorder Among Children Aged 8 Years - Autism Developmental Disabilities Monitoring Network.

Current Autism Prevalence in the U.S.

The newly released report by the CDC estimates that 1 in 44 children have autism in the United States, indicating a 241% increase in autism prevalence since 2000 when autism prevalence was 1 in 150.

Key points from the report on 2018 data released 2021 CDC's report show that:

  • There is a 22.7% increase since the last report on 2016 data released in March 2020.
    • This is a 241% increase since the Autism and Developmental Disabilities Monitoring Network (ADDM) was created.
  • California has the highest prevalence in the 11 surveyed sites, surpassing the previous leading state, New Jersey.  California's autism prevalence of 1 in 26 for 8-year olds.
  • Overall prevalence rates are similar across race and ethnicity with the following exceptions:
    • American Indian/Alaska Native children have a higher ASD prevalence than White Children.
    • At multiple survey sites, Hispanic children had lower ASD prevalence rates than White or Black children

What is the ADDM?

Back in 2000, the CDC created a monitoring network in order to track autism prevalence over time. This monitoring network is called the Autism and Developmental Disabilities Monitoring Network (ADDM). Before ADDM monitoring the CDC performed surveillance on the autism prevalence.

Frequently Asked Questions From the 2016 Survey

Many people come to us with questions about autism prevalence. Below you will find answers to some of the most common questions we receive.

What causes autism?

While the cause of autism remains unclear, current studies show genetics and environment both play a role. The CDC also acknowledges that there are "many different factors that make a child more likely to have an ASD, including environmental, biologic and genetic factors," which is why they have launched the SEED study to learn more about the risk factors and causes of autism.

Is there really an increase in prevalence or is this just better diagnosing?

No. While it is true that the definition of autism was expanded to include PDD-NOS and Asperger's, the CDC states that:

"It is unclear exactly how much of this increase is due to a broader definition of ASD and better efforts in diagnosis. However, a true increase in the number of people with an ASD cannot be ruled out. We believe the increase in the diagnosis of ASD is likely due to a combination of these factors.

We do know that ASD are more common than we thought before and should be considered an important public health concern. There is still a lot to learn about ASD. In addition, increased concern in the communities, continued demand for services, and reports estimating a prevalence of about 1.7 percent show the need for a coordinated and serious national response to improve the lives of people with ASD."

National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention. (2019) Frequently Asked Questions: Is there an ASD Epidemic? Retrieved from

National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention. (2019) Frequently Asked Questions: Is there an ASD Epidemic? Retrieved from

There are a lot of different autism prevalence rates floating around out there. Which one is the official rate?

The prevalence rate that is considered "official" is the one that is released by the CDC.
Other organizations, such as the National Survey of Children's Health (NSCH) and the National Health Interview Survey (NHIS), use different methods to collect their data and look at different age groups when determining prevalence rates. This is why their autism prevalence rates differ from the CDC's.

The 1 in 44 rate doesn't reflect what I see at my child's school, so how do they come up with the rate?

Prevalence rates are not a census. They do not represent the entire population of children with autism in the United States. They are an estimate based on a sampling of communities throughout the United States.

Who is included in the CDC's sample when they determine the rate?

The CDC calculates autism prevalence based on the following data:

  1. Health and special education records of 8-year-old children
  2. These records were collected from specific sites located in the following 11 states:
  • Arizona
  • Arkansas
  • Colorado
  • Georgia
  • Maryland
  • Minnesota
  • Missouri
  • New Jersey
  • North Carolina
  • Tennessee
  • Wisconsin

When did the CDC collect all of the data to determine the rate?

The CDC collected the data to determine the current rate back in 2016. It takes the CDC about 4 years to analyze the data and release a new prevalence rate.