California autism statistics, and what each one measures.
Three public systems count autism in California in different ways: CDC surveillance, the state's public schools, and its regional centers. Their numbers differ because they answer different questions. Here they are side by side, with the source for each.
How common autism is: CDC surveillance
Every two years, CDC's Autism and Developmental Disabilities Monitoring (ADDM) Network reviews health and education records for 8-year-olds in selected communities. California's site covers specific communities, not the whole state.
Specific communities only. Not a statewide rate.
Centers for Disease Control and Prevention95% confidence interval 31.6–32.9
Centers for Disease Control and PreventionShow the numbers
| Period | California site | ADDM sites combined |
|---|---|---|
| 2000 | — | 6.7 (6.3–7.0) |
| 2002 | — | 6.6 (6.3–6.8) |
| 2004 | — | 8.0 (7.6–8.4) |
| 2006 | — | 9.0 (8.6–9.3) |
| 2008 | — | 11.3 (11.0–11.7) |
| 2010 | — | 14.7 (14.3–15.1) |
| 2012 | — | 14.8 (14.4–15.2) |
| 2014 | — | 16.8 (16.4–17.3) |
| 2016 | — | 18.5 (18.0–19.1) |
| 2018 | 38.9 (35.9–42.1) | 23.0 (22.3–23.6) |
| 2020 | 44.9 (41.7–48.2) | 27.6 (26.9–28.3) |
| 2022 | 53.1 (49.6–56.7) | 32.2 (31.6–32.9) |
What this measures: Applies only to the sampled surveillance communities for each year. A state-named ADDM site covers specific communities, not the whole state, and is not a county or statewide rate.
California public schools
Schools count students with an IEP whose primary disability category is autism. This reflects who has been found eligible for special education under that category, which depends on identification, services, and record-keeping as well as on how common autism is.
147,004 in 2022-23
California Department of EducationShow the numbers
| Period | California |
|---|---|
| 2022-23 | 147,004 |
| 2023-24 | 167,341 |
| 2024-25 | 187,499 |
| 2025-26 | 205,789 |
What this measures: Counts students whose primary special-education eligibility category is reported by public schools on Census Day. It is not a count of all autistic children, not a clinical diagnosis count, and not a prevalence rate.
Bay Area counties, 2025-26
| County | Primary category: autism | Share of special education |
|---|---|---|
| Alameda County | 7,477 | 25.6% |
| Contra Costa County | 6,030 | 23.9% |
| Marin County | 601 | 14.5% |
| Napa County | 585 | 20.2% |
| San Francisco County | 2,253 | 24.0% |
| San Mateo County | 2,399 | 21.1% |
| Santa Clara County | 7,310 | 24.4% |
| Solano County | 2,251 | 23.2% |
| Sonoma County | 2,351 | 21.0% |
How this compares with the federal count
California also reports its students to the U.S. Department of Education under IDEA, on a fall child count date and in federal age groups. That is the figure used to compare states. It will not match CDE's Census Day count: the latest federal file covers 2024-25 rather than 2025-26, the count dates differ, and the federal file splits students into preschool (3–5, not in kindergarten) and school age (5 in kindergarten through 21).
California regional centers
People served by each of the state's 21 regional centers whose record includes an autism diagnosis, through Nov 30, 2025. Each center is shown separately; figures cover whole catchment areas, not counties.
| Regional center | Serves | Autism diagnosis on record |
|---|---|---|
| San Diego Regional Center | Imperial, San Diego | 23,260 |
| North Los Angeles County Regional Center | Los Angeles (part) | 21,837 |
| Inland Regional Center | Riverside, San Bernardino | 18,267 |
| Alta California Regional Center | Alpine, Colusa, El Dorado, Nevada, Placer, Sacramento, Sierra, Sutter, Yolo, Yuba | 16,390 |
| Regional Center of the East Bay | Alameda, Contra Costa | 14,192 |
| Central Valley Regional Center | Fresno, Kings, Madera, Mariposa, Merced, Tulare | 14,137 |
| Regional Center of Orange County | Orange | 12,720 |
| South Central Los Angeles Regional Center | Los Angeles (part) | 11,581 |
| Harbor Regional Center | Los Angeles (part) | 10,964 |
| Valley Mountain Regional Center | Amador, Calaveras, San Joaquin, Stanislaus, Tuolumne | 10,639 |
| Tri-Counties Regional Center | San Luis Obispo, Santa Barbara, Ventura | 8,723 |
| San Andreas Regional Center | Monterey, San Benito, Santa Clara, Santa Cruz | 8,473 |
| Eastern Los Angeles Regional Center | Los Angeles (part) | 8,317 |
| San Gabriel/Pomona Regional Center | Los Angeles (part) | 7,857 |
| Frank D. Lanterman Regional Center | Los Angeles (part) | 7,522 |
| Kern Regional Center | Inyo, Kern, Mono | 7,243 |
| Westside Regional Center | Los Angeles (part) | 5,995 |
| Far Northern Regional Center | Butte, Glenn, Lassen, Modoc, Plumas, Shasta, Siskiyou, Tehama, Trinity | 5,273 |
| North Bay Regional Center | Napa, Solano, Sonoma | 4,935 |
| Golden Gate Regional Center | Marin, San Francisco, San Mateo | 3,651 |
| Redwood Coast Regional Center | Del Norte, Humboldt, Mendocino, Lake | 2,358 |
What this measures: Counts people served by a regional center, not everyone with the condition. One person can have several diagnoses, so these counts cannot be added together. Figures cover the center's whole catchment area and are not split by county.
Map of regional centersDifferent systems, different questions.
- Who is counted
- 8-year-olds in monitored communities who meet CDC's case definition after record review
- Answers
- How common is autism among children in these communities?
- Does not answer
- How common autism is in a specific county, school district, or the whole state
- Who is counted
- Students ages 3–22 with an active IEP whose primary category is autism
- Answers
- How many students receive special education under the autism category?
- Does not answer
- How many autistic children live in an area. Many autistic students are served under another category or have no IEP.
- Who is counted
- People of all ages receiving regional center services whose record includes an autism diagnosis
- Answers
- How many people a regional center serves with autism on record?
- Does not answer
- How many autistic people live in its area, or how many live in any single county
Statistics can't tell you about your child.
If you have questions about your child's development, an evaluation is how you get answers. Start with what you're noticing.
Where these numbers come from
Figures are copied from public files without adjustment. Suppressed cells stay blank. Each source's own definitions apply.
Read the methodology- CDC surveillance · ADDMCDC Autism Data Visualization Tool — prevalence estimates over timeCenters for Disease Control and Prevention, Autism and Developmental Disabilities Monitoring (ADDM) Network
- Editions used
- cdc-data-viz
- Retrieved
- Oct 16, 2026
- License
- Public domain (U.S. Government work)
- Pipeline run
cdc-addm-20261016180038-0d33
- Public schools · CDESpecial Education Enrollment by Program SettingCalifornia Department of Education, DataQuest Special Education Enrollment by Program Setting downloadable files
- Editions used
- 2025-26
- Retrieved
- Oct 16, 2026
- License
- Public data; CDE conditions of use
- Pipeline run
cde-sped-20261016175955-607a
- Public schools · U.S. Dept. of EducationIDEA Section 618 State Part B Child Count and Educational EnvironmentsU.S. Department of Education, Office of Special Education Programs, IDEA Part B Child Count and Educational Environments Collection (EDFacts file specifications 002 and 089)
- Editions used
- 2024-25
- Retrieved
- Oct 16, 2026
- License
- Creative Commons CC0
- Pipeline run
idea-partb-child-count-20261016193854-6789
- Regional centers · DDSDDS Consumers by Diagnosis, Early Start Consumers, and Regional CenterCalifornia Department of Developmental Services, via the California Open Data Portal (CC BY)
- Editions used
- ckan-2026-10-08
- Retrieved
- Oct 16, 2026
- License
- Creative Commons Attribution (CC BY)
- Pipeline run
dds-diagnosis-20261016180057-88f1