Autism rates in California are among the highest measured anywhere in the United States. The CDC’s latest count found autism in 53.1 of every 1,000 eight-year-olds at its California site in 2022, about 1 in 19. California’s Department of Developmental Services (DDS) served 222,586 autistic people in fiscal year 2024-25.
Quick answer
Autism rates in California: The CDC’s 2022 data found autism in about 1 in 19 eight-year-olds in its California site in San Diego County, versus 1 in 31 across all 16 sites. DDS regional centers served 222,586 autistic people in 2024-25, up 162 percent in ten years. Better early screening and access to evaluations explain part of the gap.
Last checked: November 10, 2026. This is general information, not legal or medical advice.
What are the autism rates in California right now?
There is no single statewide autism rate. Two official sources count autism in different ways. The CDC’s Autism and Developmental Disabilities Monitoring (ADDM) Network estimates how many children have autism in selected communities. DDS counts the people its 21 regional centers serve under the Lanterman Act.
Both point the same way. The CDC’s California site has had the highest rate in its network since it joined in 2018. In 2024, autism became the largest diagnosis among regional center clients for the first time.
This page updates our archived California’s Autism Increase page, whose figures date from December 2014. That original text stays below, unchanged. In December 2014, DDS counted more than 75,000 autism cases. The 2024-25 count is nearly three times higher.
What the CDC ADDM data show for California
The CDC’s latest report, published in April 2025, uses records from 2022. Across 16 sites, 32.2 of every 1,000 eight-year-olds had autism, or 1 in 31. Site rates ranged from 9.7 per 1,000 in Laredo, Texas, to 53.1 per 1,000 in California.
The California site is not the whole state. It covers part of one county in metropolitan San Diego. The CDC says its sites are not nationally representative, so the figure does not describe every California county.
Rates for 4-year-olds
The same report tracked 4-year-olds. Across all sites, 29.3 per 1,000 had autism. California was again highest at 60.6 per 1,000, about 6 percent, against 12.9 per 1,000 at the lowest site in Indiana.
Children are also being identified earlier. Children born in 2018 were 1.7 times as likely to be diagnosed or found eligible by age 4 as children born in 2014.
Boys and girls
Nationally, the CDC found 49.2 per 1,000 boys and 14.3 per 1,000 girls, a ratio of 3.4 to 1. DDS reports a similar split among its California autism caseload: 77 percent male and 23 percent female.
| Source | What it measures | Latest figure (year) |
|---|---|---|
| CDC ADDM, 8-year-olds | Health and school records in part of San Diego County | 53.1 per 1,000, about 1 in 19 (2022) |
| CDC ADDM, 4-year-olds | Same records, younger group | 60.6 per 1,000 (2022) |
| CDC ADDM, all 16 sites | Multi-state comparison, not national | 32.2 per 1,000, 1 in 31 (2022) |
| DDS autism caseload | People served by regional centers | 222,586 (FY 2024-25) |
| DDS 8-year-old estimate | Regional center clients age 8 divided by county population | 2.60% statewide (2025) |
How many people have autism in California? The DDS caseload
DDS served 222,586 people with an autism diagnosis in fiscal year 2024-25, out of 414,487 people eligible for Lanterman Act services. That is 54 percent of the caseload, up from 33 percent in 2014-15. Over the same ten years, the autism caseload grew 162 percent.
The figures come from the DDS Autism Annual Report to the Legislature (April 2026). Other details from that report:
- 78.7 percent of autistic regional center clients are under 22. Children ages 6 to 9 are the largest group.
- Autism shares vary by regional center, from 36 percent at Golden Gate to 63 percent at Frank D. Lanterman, Harbor and North Los Angeles County.
- 52.5 percent of autistic clients who entered between 2017-18 and 2024-25 became eligible before age 3.
The DDS count is not every autistic Californian. It leaves out people who are not eligible for regional center services and people who never applied.
County rates for 8-year-olds
DDS also estimates a rate for 8-year-olds by dividing its autistic clients at that age by each county’s population. The statewide figure for 2025 was 2.60 percent. County figures ranged widely: 3.55 percent in Los Angeles, 3.11 percent in San Diego, 0.91 percent in San Francisco and 0.44 percent in Marin.
Why is autism higher in California?
The CDC does not say California children are more likely to be autistic. Its report says differences between sites “might be due to differences in availability of services for early detection and evaluation.” Research has not shown that living in a certain community raises a child’s chance of autism.
The report names three California factors:
- Early screening. San Diego uses the Get SET Early model, which has trained hundreds of local pediatricians to screen toddlers and refer them for assessment early.
- Regional centers. California has regional centers throughout the state that provide evaluations and service coordination.
- Insurance coverage. Whether children have insurance that pays for evaluations and early intervention can change how many are identified.
Older California research points the same way. A 2009 study of DDS records by King and Bearman estimated that about one quarter of the state’s autism caseload growth from 1992 to 2005 came from diagnostic change. Many people once listed with intellectual disability were later diagnosed with autism. Researchers still debate the rest.
Why CDC and DDS numbers differ
The CDC’s San Diego rate (5.31 percent) is about twice the DDS statewide estimate for 8-year-olds (2.60 percent). The CDC counts a child with an autism diagnosis, autism special education eligibility or an autism medical code. DDS counts only people a regional center found eligible. A child served only through an IEP at school appears in the CDC count but not in the DDS one.
What do the numbers mean for families?
Autism is common, and California has a large system to evaluate and support autistic people. The same growth also means long waits for some evaluations and services.
- Act early. Over half of the autistic children who entered regional centers since 2017 became eligible before age 3. Learn the early signs of autism in toddlers and ask your pediatrician about screening at 18 and 24 months.
- Use Early Start. Children under 3 can get services for a developmental delay without an autism diagnosis through the Early Start program in California.
- Know the eligibility rules. A diagnosis alone does not open regional center services. Our guide to regional center eligibility for autism explains the tests.
- Understand the diagnosis. If autism is new to your family, start with our plain-language guide to what autism spectrum disorder is.
Read the full CDC report in CDC’s MMWR on autism prevalence among children aged 4 and 8 years (2022 data).
Frequently asked questions
Are autism rates higher in California than in other states?
In CDC data, yes. California’s site had the highest rate of the 16 sites in 2022: 53.1 per 1,000 eight-year-olds, against 32.2 across all sites. The CDC links the gap to early screening, evaluation services and insurance coverage rather than to any proven difference in risk.
Is autism increasing in California?
The number of people identified keeps rising. The DDS autism caseload grew 162 percent between 2014-15 and 2024-25. Studies show that diagnostic change and earlier identification explain part of that rise. Researchers still debate how much reflects a true change in how many people are autistic.
When will new CDC autism data come out?
The ADDM Network reports every two years. The April 2025 report used 2022 records, and no newer report had been published by November 2026.
Does the DDS number include autistic adults?
It includes adults who are regional center clients; 21.3 percent of the 2024-25 autism caseload was 22 or older. It leaves out adults who were never found eligible or never applied, so the true number of autistic adults in California is higher.
Next step
For the full picture of evaluations, regional centers and school services, start with our guide to autism services in California.
Questions about what the numbers mean for you? Call the Autism Society of California information line at 1-800-869-7069, or connect with families near you through the Autism Society of California’s local affiliates.
Original article (archived)
Archived page. The figures date from December 2014, and the wording reflects that time. The three charts on the original page and the linked PDF were not preserved in the archive, so only their titles remain.
Autism Explosion: California Department of Developmental Services Autism Cases, 1989-2014 (chart not preserved)
December 2014 California Dept of Developmental Services CDER case records, by county (file not preserved)
This PDF, a report that is issued quarterly, shows Regional Center developmental disability cases, statewide and by county. As of December 2014, California counts more than 75,000 DDS Autism cases.
For every one Californian with DDS-eligible Autism in 1990, there are more than 20 today: (chart not preserved)
California Autism Population, by Birth Year, DDS Cases Only (chart not preserved)