An estimated 2.21% of adults in the United States have autism spectrum disorder, which translates to roughly 5.4 million adults based on current population figures. Among children, the CDC’s most recent data from 2022 identifies about 1 in 31 eight-year-olds as having autism. Combined, millions of Americans across all age groups are living with autism, making it one of the most common developmental conditions in the country.
Prevalence in Children
The CDC tracks autism prevalence in children through its Autism and Developmental Disabilities Monitoring (ADDM) Network, which collects data from 16 sites across the country. The most recent report, based on 2022 data, found that about 3.2% of eight-year-olds, or 1 in 31, had been identified with autism. That figure has climbed steadily over the past two decades. In the early 2000s, the estimate was closer to 1 in 150. By 2012, it was 1 in 69. The increase reflects a combination of broader diagnostic criteria, greater awareness among parents and clinicians, and improved screening, particularly in communities that were historically underserved.
Prevalence also varies dramatically by location. Across the 16 ADDM sites, rates ranged from 1 in 103 children in the Laredo, Texas area to 1 in 19 in parts of California. These differences likely reflect how aggressively communities screen for autism and how accessible diagnostic services are, rather than true differences in how often autism occurs.
Prevalence in Adults
A CDC study using 2017 data estimated that 2.21% of U.S. adults have autism. That percentage varied modestly by state, from 1.97% in Louisiana to 2.42% in Massachusetts. The states with the largest total numbers were California (roughly 702,000 adults), Texas (about 450,000), New York (342,000), and Florida (329,000), reflecting their large overall populations.
Many adults with autism were never diagnosed as children, especially those born before screening became routine. Some received other diagnoses first, such as anxiety, ADHD, or intellectual disability, and were only identified as autistic later in life. This means the adult estimate is almost certainly an undercount.
Differences by Race and Ethnicity
Autism was once diagnosed far more often in white children, but that gap has reversed. The CDC’s 2022 data shows white children now have the lowest identified prevalence at about 27.7 per 1,000. Asian or Pacific Islander children had the highest rate (38.2 per 1,000), followed by American Indian or Alaska Native children (37.5), Black children (36.6), Hispanic children (33.0), and multiracial children (31.9).
This shift is significant. For years, lower rates in non-white communities reflected barriers to diagnosis, not lower actual occurrence. As screening has expanded and become more culturally accessible, identification rates in these groups have caught up and, in many cases, surpassed those of white children. The pattern suggests that disparities in access to evaluation still shaped earlier data.
The Narrowing Gender Gap
Autism has long been considered far more common in boys, with historical ratios around 4 to 1. That gap is shrinking fast. A large population-based study published in The BMJ found that by 2022, the cumulative male-to-female ratio for autism diagnoses had dropped to 1.2 to 1 by age 20. Among those diagnosed between 2020 and 2022, the ratio was no longer greater than 1 for individuals over age 15, meaning girls and women in that age range were being diagnosed at the same rate as boys and men.
The study projected that the gender ratio could reach full parity by 2024. Researchers point to several factors. Girls and women tend to have stronger social and communication skills on average, which can mask autistic traits and delay diagnosis. They’re also more likely to “camouflage,” picking up behavioral cues from peers and mimicking speech or facial expressions. Co-occurring conditions like anxiety or depression can also overshadow autism in clinical settings, leading to missed diagnoses. The rising rate of female diagnoses likely reflects better recognition of how autism presents in girls and women rather than an actual increase in occurrence.
Why the Numbers Keep Rising
The steady climb in autism prevalence over the past two decades is one of the most common sources of confusion. The increase is driven primarily by changes in how autism is defined, recognized, and diagnosed rather than by a true surge in the condition itself.
When the diagnostic manual shifted from its fourth edition to its fifth (DSM-5) in 2013, several previously separate diagnoses, including Asperger’s syndrome and pervasive developmental disorder not otherwise specified, were folded into a single autism spectrum disorder category. Research comparing the two systems found that roughly 9% to 54% of people diagnosed under the older criteria wouldn’t meet the newer ones, with a median of about 30%. But the broader public awareness that came with the DSM-5 era, combined with better screening tools and expanded access, has more than offset any narrowing of the clinical definition.
Greater screening in communities of color, increased recognition in girls, and a growing willingness among adults to seek evaluation have all contributed to the rising numbers. Each time the CDC updates its estimates, the increase primarily reflects people who were always autistic but are now being identified.
Economic Scale
The financial impact of autism in the U.S. is substantial. A CDC-published forecast estimated that combined costs, including medical care, support services, and lost productivity, would reach approximately $461 billion annually by 2025. That figure represents roughly 1.6% of the nation’s GDP. The range of estimates is wide, from $276 billion to over $1 trillion, depending on assumptions about prevalence and per-person costs. These numbers encompass not just healthcare but also special education, workplace accommodations, and the economic impact on family caregivers who reduce work hours or leave jobs entirely.