Frequently Asked Questions
1. Why do we need to know how many children have autism?
Findings from the MN-ADDM help us understand more about the number of children with autism, the characteristics of those children, and the age at which they are first evaluated and diagnosed.
MN-ADDM’s findings can be used to promote early identification of autism, plan for autism services/supports, identify training needs, guide future autism research, and inform policies promoting improved outcomes in health care and education for individuals with autism.
2. Does the autism prevalence of 1 in 28 represent all children in Minnesota?
We do not know the estimated autism prevalence rate across the entire state of Minnesota. To estimate this rate, we’d need to expand the geographic region. These data tell us that the estimated prevalence rate of autism for 8-year-olds in parts of Anoka, Hennepin, and Ramsey counties is 1 in 28. The rate for 4-year-olds is 1 in 40.
3. Is autism prevalence increasing in Minnesota?
Autism prevalence increased for both 4- and 8-year-olds in 2022 compared to 2020. Among 8-year-olds, since the UMN joined the ADDM network in 2014, autism rates in Minnesota have either increased or remained stable. Among 4-year-olds, prevalence rates have ranged from 1 in 53 in 2020, 1 in 44 in 2018, and 1 in 40 in 2022.
4. Do these results tell us anything about the reasons for changes in prevalence of autism in three Minnesota counties?
While tracking autism prevalence helps us understand how many children are identified, these data do not explain why prevalence increased in 2022. Nationally, rates have risen since 2000, likely due to broader definitions, greater awareness, and improved identification—especially in historically underserved communities—though a true increase cannot be ruled out.
5. What can you tell us about autism prevalence in the Somali community?
MN-ADDM builds on earlier work examining autism prevalence in Somali and non-Somali children in Minneapolis. That 2014 study found differences in co-occurring intellectual disability by ethnic group. Current MN-ADDM data on Somali and Hmong children have not yet been analyzed—please check the website for updates. Previous studies used different methods and populations, so direct comparisons should be made with caution.
Previous MN studies have specifically looked at autism prevalence and the Somali community. It is important to know that these two previous studies used different methods and focused on different groups of children. Thus, making comparisons should be avoided. You can learn more about these two previous studies by clicking on the links provided here:
Autism Spectrum Disorders Among Preschool Children Participating in Minneapolis Public Schools Early Childhood Special Education Programs PDF 
. This report provided information on the rates of preschool special education program participation in MPS only.
Data Collection Approach
6. What data was gathered to determine the results?
The information was gathered from health and education records of children who lived in parts of Anoka, Hennepin, or Ramsey counties and who were 4-, 8-, or 16-years-old in 2022.
7. Why is the data from 2022 and not more recent?
ADDM uses a rigorous and labor-intensive data collection process. It takes a lot of time to gain access to the data and to conduct the detailed review and analyses for the entire ADDM network.
8. How and where was this information collected?
The ADDM Network estimates the number of children with autism using a systematic record review method. Records that included various billing codes from the International Classification of Disease, Ninth Revision (ICD-9) or International Classification of Diseases, Tenth Revision (ICD-10) or special education eligibility codes were requested from health and education sources. Children ages 4 or 8 who had a parent or guardian who lived in one of the surveillance areas during 2022 were classified as having autism if they had:
- a written autism clinical diagnosis by a qualified professional,
- a special education classification of autism, OR
- an autism ICD code obtained from administrative or billing information
9. Why was the data not collected statewide?
MN-ADDM was funded to estimate the prevalence of 4-, 8-, and 16-year-olds with autism in Anoka, Hennepin, and Ramsey counties. This project also identified differences in prevalence, characteristics, and age of diagnosis across demographic groups, including two large communities unique to the area – Somali and Hmong children.
The MN-ADDM geographic area is limited by availability of resources. Having access to a larger geographic area would increase the MN-ADDM population size included in the identification of prevalence. This would provide more information about geographic variation among regions and support conclusions about differences in prevalence estimates and disparities.
MN-ADDM is a valuable resource for the state of Minnesota, but it will need ongoing funding to support expansion into more communities in the state that would enable us to provide statewide estimates.
10. Why study 4- and 8-year-olds instead of adults?
The CDC's ADDM Network methodology is standardized across all data years and has estimated the prevalence of autism for 8-year-olds since its first data cycle and continues to do so. By age 8, a child with autism should have been identified either clinically or through the education system. 2018 was the first year that all ADDM Network sites were funded to collect data on 4-year-old children.
In 2022 and 2024, MN-ADDM is tracking prevalence among 16-year-olds in Minnesota and will share the results in 2025 data release. This will allow us to understand the needs and characteristics of autistic teens to inform supports for transition to adulthood.
11. How have the quality and accuracy of results been ensured?
Established protocols have been followed in the planning, gathering, and analysis of all data. Specifically, the standard criteria used as part of the ADDM Network method ensures that all records are evaluated and reviewed in the same way and that all children are defined as having autism using the same definition. The CDC monitors the project to ensure adherence to CDC methods.
12. What role has the community had in the project?
MN-ADDM collaborates with a wide variety of community autism organizations and several Minnesota state agencies including the Minnesota Departments of Education (MDE), Minnesota Department of Human Services (DHS), and Minnesota Department of Health (MDH). School districts and clinics are important community partners. MN-ADDM staff are regularly out in the community sharing results and listening to community needs.
13. Why does MN-ADDM focus on the Somali and Hmong populations in its project?
It is important for us to understand autism prevalence across different communities in Minnesota. This project builds on earlier ICI work entitled the Minneapolis Somali Autism Prevalence Project, which estimated the prevalence of autism among Somali and non-Somali children in Minneapolis. That project is the largest project to date to look at the number and characteristics of Somali children with autism in any community within the United States. The findings of that 2014 project showed notable differences in autism prevalence and co-occurring conditions, such as intellectual disability, between children from different ethnic groups in Minneapolis.
Other studies conducted in the United States have identified disparities among children with autism across communities in terms of age of diagnosis and access to and utilization of services.
Publications from the Minneapolis Somali Autism Prevalence Project:
14. How does MN-ADDM determine autism prevalence among Somali and Hmong children in Minnesota?
MN-ADDM collected racial and ethnic data per CDC methodology, but it also looked at autism prevalence in two racial/ethnic groups with high populations in Minnesota: Somali and Hmong. To do this, data is gathered on language spoken in the home as documented in health and educational records. Population denominators for Somali and Hmong children are determined from data from the Minnesota Department of Education on the percentage of students in each district who speak Hmong or Somali in the home.
Critical Issues and Next Steps
15. Is this an epidemic or crisis? Why are more children being identified with autism?
A large number of children are identified as having autism and the prevalence rates have certainly increased over time. Research has found several factors that have contributed to the increase in autism prevalence: (1) changes in diagnostic criteria that have expanded to include individuals with subtler characteristics; (2) increased awareness, and (3) policy changes that increased people’s access to insurance coverage for autism diagnoses and intervention services. Additionally, the ADDM methodology changed in 2018, and since then new sites were added, so prevalence across years may not be directly comparable. Furthermore, our geographic area in Minnesota has increased over time. These factors may not explain all of the increased prevalence, and it is possible that more children truly have autism than in the past. Tracking prevalence is important to help us understand more about children with autism; however, this data does not tell us anything about the reasons why autism prevalence is high within the United States and in Minnesota.
16. What is the cause of autism? What is being done to find a cause(s)?
MN-ADDM was designed to identify the prevalence of autism in 4-, 8-, and 16-year-olds in Anoka, Hennepin, and Ramsey counties. Its purpose was not to figure out the causes of autism. It can help MN-ADDM understand who lives with autism so it can advocate for resources and policies that support families and individuals with autism.
The causes of autism are complex. Current evidence supports that autism arises from multiple factors or combinations of factors. Large-scale studies, including twin and family studies, strongly support the role of heritability, but environmental factors like advanced parental age, low birth weight, or prenatal exposure to certain substances may also increase risk. The science continues to evolve.
There are many researchers interested in understanding the causes of autism, including some at the University of Minnesota who are looking at the genetics of autism and at early brain development in children at increased likelihood for autism.
17. Do immunizations cause autism?
Research has not found evidence that vaccines cause autism. The original study that suggested a link was later found to be untrue and the article retracted because the researcher misrepresented his findings and used unethical methods. MDH provides more information about this topic, but we also recommend you talk with your child's pediatrician about your concerns. Visit https://www.health.state.mn.us/immunize .
18. Immunization rates for Somali children have gone down over time, so why did autism rates go up?
This tells us that avoiding vaccines does not prevent autism in children. We understand that parents are fearful their child may develop autism and want answers for what causes autism. We know it's not vaccines, but we don't yet know what all of the causes of autism are, and finding those answers would help put to rest fears about vaccines. We hope that resources can be dedicated to understanding what really does cause autism and, even more importantly, what treatments, supports, and services work to improve the lives of people with autism and their families. It is important to talk with your doctor at your well child visits about your child's development and about any concerns you might have about vaccinations.
19. Why is it important to continue studying autism prevalence?
ADDM data reflects community and policy practices. Documenting prevalence is a necessary step towards establishing the need for developing more services and supports to meet the demand in Minnesota and for identifying the need for more research. While many children have been diagnosed with autism, MN-ADDM data helps to better understand differences in prevalence across groups. Continuing to expand our knowledge about prevalence helps us move closer to being able to answer these types of questions with confidence and to better plan for services and supports for individuals with autism and their families.
20. Next steps for the project
The MN-ADDM project builds on national efforts to understand autism by tracking how and when children are identified in Minnesota and studying differences across communities. MN-ADDM collaborates with community partners to improve early identification, especially in under-identified groups and communities.
Through partnerships with Learn the Signs. Act Early and Help Me Grow MN, the project has developed and translated outreach materials, including a previously developed autism short film series to raise awareness and support access to evaluation and services.
MN-ADDM continues to work with state agencies, providers, educators, and families through the MN Autism Interagency Team to improve service coordination. Families can access supports through local schools, Help Me Grow MN , county agencies, and resources like MN Autism Portal and Autism Society of Minnesota