About 3.2% of American children (1 in 31) have been identified with autism spectrum disorder, based on the most recent CDC data from 2022. For adults, the estimated rate is 2.21%. These numbers have risen sharply over the past two decades, driven largely by broader diagnostic criteria, better screening, and growing awareness rather than a true spike in occurrence.
Current Rates in Children
The CDC’s Autism and Developmental Disabilities Monitoring (ADDM) Network, which tracks autism among 8-year-olds across 16 sites nationwide, reported an overall prevalence of 32.2 per 1,000 children for the 2022 surveillance year. That translates to roughly 1 in 31 kids, or 3.2%. This is the highest figure the network has ever recorded.
The number has climbed steadily. In 2000, the ADDM Network estimated about 1 in 150 children had autism. By 2012 it was 1 in 69, and by 2018 it was 1 in 44. The jump to 1 in 31 in just a few years reflects not an epidemic but a system that has gotten significantly better at identifying autistic children, particularly among groups that were historically underdiagnosed.
Autism in Adults
A CDC study using 2017 data estimated that 2.21% of U.S. adults have autism. That percentage varies modestly by state, ranging from 1.97% in Louisiana to 2.42% in Massachusetts. The states with the largest estimated numbers of autistic adults are California (roughly 702,000), Texas (about 450,000), New York (around 342,000), and Florida (approximately 329,000).
The adult figure is almost certainly an undercount. Many adults, especially women and people of color, grew up in an era when autism was defined much more narrowly. A significant number of autistic adults have never received a formal diagnosis.
Differences by Sex
Boys are diagnosed with autism far more often than girls. Among 8-year-olds in the 2022 ADDM data, prevalence was 49.2 per 1,000 for boys compared to 14.3 per 1,000 for girls, a ratio of about 3.4 to 1. That gap has narrowed somewhat over time: the male-to-female ratio was 4.2 in 2018 and 3.8 in 2020.
The narrowing ratio doesn’t tell the whole story, though. In absolute terms, the gap between boys and girls actually widened, from a difference of 27.7 per 1,000 in 2018 to 34.9 per 1,000 in 2022. Both groups are being identified at higher rates, but the rate among boys is climbing faster in raw numbers.
A large birth cohort study published in The BMJ found that the sex gap shrinks considerably with age. For children diagnosed between 2020 and 2022, the male-to-female ratio held steady at around 3 up to age 10 but was no longer above 1 for individuals diagnosed after age 15. Girls and women are increasingly being recognized later in life, often after years of masking their traits. Projections from the study suggested the cumulative ratio could reach near parity by age 20 as early as 2024.
Wide Variation by Location
Where you live in the U.S. has a surprising effect on how likely a child is to be identified with autism. Across the 16 ADDM Network sites, prevalence ranged from 1.0% (1 in 103) in Laredo, Texas, to 5.3% (1 in 19) in California. That’s a fivefold difference.
This variation doesn’t mean autism is more common in California than in South Texas. It reflects differences in how aggressively communities screen for autism, how many evaluation specialists are available, and how schools and healthcare systems record and share diagnoses. Areas with more robust early intervention programs and better access to developmental pediatricians tend to report higher prevalence simply because they find more cases. In communities with fewer resources, many autistic children go unidentified or receive a different diagnosis entirely.
How the CDC Tracks These Numbers
The ADDM Network doesn’t survey families or rely on self-reported diagnoses. Instead, it uses a population-based record review method. Researchers in each site pull together health records, school records, and early intervention service data, then review them systematically to identify children who have received an autism diagnosis, an autism special education classification, or a relevant medical code from a community provider. This approach captures children across an entire geographic area rather than sampling from clinics, which makes it more comprehensive than doctor-visit-based estimates.
The network tracks 8-year-olds specifically because that age is old enough for most cases to have been identified but young enough to still be captured in pediatric records. More recent reports have also begun tracking 4-year-olds to get a better picture of early identification.
The Cost of Support and Services
Autism-related care is expensive, and costs have been rising faster than the overall rate of diagnosis. For children ages 3 to 7 on employer-sponsored insurance, average annual healthcare spending rose 51% between 2011 and 2017, climbing from about $13,200 to nearly $20,000 per child. The biggest driver was outpatient behavioral therapy, where average spending per child jumped from roughly $1,750 to $8,300 over that same period, a 376% increase.
By 2017, about 14% of young children with autism on private insurance were racking up at least $20,000 a year in behavioral therapy costs alone, and nearly 6% exceeded $50,000. These figures only cover privately insured children. They don’t include families on Medicaid or those paying out of pocket, so the full economic picture is even larger. As the identified population grows and insurance mandates for autism therapy expand, total spending on autism services across the country continues to climb.