Millions of autistic children in the US are not receiving equal access to services, and the research meant to address this problem has significant blind spots, according to a new review published in Frontiers in Psychiatry. The findings raise concerns about whether existing evidence can truly guide efforts to close persistent gaps in autism care.
The review examined 60 studies conducted over two decades, all of which used Medicaid claims data to investigate disparities in autism services. Medicaid is one of the most important sources of healthcare coverage for autistic people in the US, partly because receiving an autism diagnosis can itself establish eligibility for the programme, regardless of household income.
Researchers found that the studies overwhelmingly focused on school-aged children and young adults between the ages of six and 21. Toddlers under three and adults over 21 were far less represented, meaning large portions of the autistic population remain poorly understood in terms of how they access and use services.
The most commonly examined services were prescription medications and therapy, including behavioural, occupational, and speech therapy. However, the review notes that many autistic people do not take medication, and pharmacological treatment is not recommended for core autism features, raising questions about whether research priorities reflect real-world needs.
Racial and ethnic diversity within the studies was also limited. Most research focused on White and Black participants, while Asian, multiracial, and Native American groups featured in fewer than 10% of studies. A large proportion of participants were simply grouped under an “other” category, which the authors argue obscures meaningful differences and erases the lived experiences of many communities.
The review also found that most studies concentrated on individual-level factors such as age, sex, and race, rather than exploring the broader social and structural forces that shape access to autism care. Factors such as language barriers, immigration status, family circumstances, and provider availability were rarely examined, even though these are known to influence whether families can navigate the healthcare system effectively.
The authors argue that this narrow focus risks placing the blame for unequal service use on individuals, rather than on the systemic barriers that drive those inequalities. Without understanding the wider social context, efforts to improve autism services may miss the people who need support most.
The data used across the reviewed studies also tended to be outdated, with much of it drawn from before 2015. Given how significantly healthcare policy and autism diagnosis practices have evolved, the researchers caution that current trends may not be well captured by the existing evidence base.
The review calls for future research to analyse more recent Medicaid data, oversample underrepresented communities, and integrate additional data sources to build a fuller picture of autism service disparities across the US.