Free CAST Autism Screening Test for Children
The Childhood Autism Spectrum Test (CAST) is a free, parent-report questionnaire that screens for autism-related traits in children ages 4 to 11. Answer 37 short yes or no questions about your child and get an instant result with clear next steps.
The CAST is designed for children 4 to 11 years old. For a younger child, take the M-CHAT-R screener instead.
Take the CAST autism screening test
Answer 37 short yes or no questions about your child. It takes about five minutes, and you get an instant result with clear next steps.
Your responses are private and are used only to share your results and next steps. The CAST is a screening tool, not a diagnosis.
CAST is © the Autism Research Centre, University of Cambridge. Used with permission.
What happens after you submit
You see your child's score and what it means right away
You can book a free evaluation on the spot if you would like one
The Alpaca Health care team reviews your responses and follows up to talk through next steps
What the CAST measures
The CAST is a parent-report questionnaire. You answer questions about your child's everyday behavior, so your child does not take a test or sit an exam.
The CAST asks 37 short yes or no questions and takes about five minutes to complete.
Social interaction
Whether your child plays and gets along with other children, shares interests, and picks up on social cues. Example question: does your child join in games with other children easily?
Communication
How your child uses and understands language, holds a back-and-forth conversation, and reads nonverbal cues. Example question: does your child take things very literally?
Imaginative play
Whether your child takes part in pretend and imaginative play with toys and ideas. Example question: does your child act out roles and make-believe with others?
Routines and repetitive behavior
Whether your child keeps strong routines, repeats movements or phrases, or gets very upset by change. Example question: does your child get very upset by small changes in routine?
Narrow interests and sensory differences
Whether your child has intense, specific interests or is unusually sensitive to sounds, textures, or lights. Example question: does your child focus intensely on one favorite topic or object?
Who should complete the CAST
A parent, caregiver, or teacher who knows the child's everyday behavior well can complete the CAST. It is designed for children 4 to 11 years old.
Tips for accurate answers
Answer for how your child usually behaves. If you have seen something only once or twice and it is not typical, answer no.
If you are unsure, picture your child across different settings, like home, school, and time with other children.
There are no right or wrong answers, and nothing is recorded. Answer every question, and it takes about five minutes.
Where the CAST comes from
The Childhood Autism Spectrum Test was developed by the Autism Research Centre at the University of Cambridge (Scott, Baron-Cohen, Bolton, and Brayne, 2002). It was first called the Childhood Asperger Syndrome Test and was renamed in 2013, when Asperger's syndrome was folded into autism spectrum disorder. It was built to identify school-age children in mainstream classrooms who may benefit from a fuller evaluation, and it is one of the most researched parent-report screeners for this age group.
That research base is why we use the CAST here, with the original wording and the published cutoff, rather than an informal quiz. To see how it compares with the M-CHAT-R and professional assessments like the ADOS-2, visit our autism evaluation guide, or browse more autism screening resources.
Signs that lead families to screen an older child
Every child develops at their own pace. These are signs that often lead families to try a screener like the CAST. Noticing a few does not mean your child is autistic; it means a closer look may help.
Ages 4 to 5
Plays alongside other children more than with them
Finds pretend and imaginative play hard
Gets very upset by small changes in routine
Focuses intensely on one favorite topic or object
Is very sensitive to sounds, textures, or lights
Ages 6 to 8
Finds it hard to make or keep friends
Takes language literally and misses jokes or sarcasm
Struggles with back-and-forth conversation
Needs routines and predictability to feel settled
Has one or two intense special interests
Ages 9 to 11
Often prefers solitary activities to group ones
Finds group work and unwritten social rules confusing
May copy others or mask to fit in, which can be tiring
Is easily overwhelmed in busy or noisy places
Talks at length about a few specific interests
If your child shows several of these signs, the CAST can help you decide whether a full evaluation makes sense.
Why autism is sometimes spotted later in childhood
Many autistic children are not identified until they are older. A child who managed one on one at home can start to struggle when school brings bigger groups, unwritten social rules, and more talking. Some children also learn to mask, copying other children to fit in, which can hide the signs for years and is tiring for the child. Being identified later is common, and it is not a failure by anyone. The CAST is designed for exactly this age, when these patterns become easier to see.
If any of this feels familiar, the free CAST above is a low-pressure way to put a number on what you are seeing. Our guide to early signs of autism explains how traits show up at different ages, and if you would rather talk it through first, you can book a free evaluation with the Alpaca Health team.
How CAST scoring works and what your score means
Scoring is standardized and always the same. Of the 37 questions, 31 count toward the total, so your child's score falls between 0 and 31. The CAST uses a single cutoff of 15.
Your child's score
What it means
What to do next
0 to 14
Below the cutoff
This screen does not suggest an elevated likelihood of autism traits right now. If you still have concerns, it is always okay to ask a professional.
No next step is needed based on this screen alone. You know your child best.
15 to 31
At or above the cutoff
A score of 15 or higher suggests it is worth arranging a full evaluation with a qualified professional. A high score is not a diagnosis, but it is a useful next step.
Talk with your pediatrician, or book a free evaluation with Alpaca Health.
Talk to the Alpaca Health teamThe CAST is a screening tool, not a diagnostic test. A score at or above the cutoff does not mean your child has autism; it means a professional evaluation is a sensible next step.
The CAST at home and at school
Because the CAST looks at how your child gets on with other children, a teacher often notices things a parent does not see, and the other way around. A parent, a caregiver, or a teacher who knows your child well can complete it.
If the result suggests a closer look, the CAST is a useful thing to bring to:
- A conversation with your child's teacher or school counselor.
- A request for a school evaluation, or an IEP or 504 plan meeting.
- Your pediatrician, who can refer your child for a full evaluation.
It is not a diagnosis, but it gives everyone a shared starting point.
From screening to diagnosis to ABA therapy
A screener is a starting point. Here is how the rest of the path usually works, and how Alpaca Health can help at each step.
1
Screen at home
The CAST above gives you a quick read on whether a full evaluation makes sense.
2
Get a professional evaluation
A qualified professional confirms a diagnosis using tools like the ADOS-2 along with your child's history. Alpaca Health offers free ADOS-2 assessments for children 18 months to 6 years old, and your pediatrician or state early intervention program can also evaluate at no cost.
3
Start support
After a diagnosis, many children begin ABA therapy. Alpaca Health matches your family with a local provider, with no waitlists and Medicaid and major insurance accepted.
Not sure where to begin? The Alpaca Health team can walk you through it.
Helpful autism resources for families
Early signs of autism in infants and toddlers
The early behaviors many parents notice first, and when to act on them.
How much ABA therapy costs
What evaluations and ABA therapy cost, and how insurance and Medicaid help.
Does Medicaid cover ABA therapy?
How Medicaid coverage works for autism evaluation and ABA therapy.
More on autism screening
Guides on screening, diagnosis, and what the results mean for your family.
ABA therapy for toddlers
How early ABA therapy works and what to expect after a diagnosis.
In-home ABA therapy
ABA therapy delivered at home, with no waitlists and Medicaid accepted.
CAST frequently asked questions
Who can complete the CAST?
A parent, caregiver, or teacher who knows the child well. The CAST is a parent-report tool, so the child does not take it themselves.
What does a high score mean?
A score of 15 or higher suggests a full evaluation is worth arranging. It is not a diagnosis, but a helpful next step.
Is the CAST free, and does an evaluation cost anything?
The screener is completely free. If your child's result suggests a closer look, Alpaca Health offers free ADOS-2 evaluations for children 18 months to 6 years old, and ABA therapy is covered by Medicaid and major insurance plans. Talk to the Alpaca Health team
What ages is the CAST for?
The CAST is designed for children 4 to 11 years old. For a younger child, use the M-CHAT-R instead.
Can I take the CAST more than once?
Yes. Children keep developing, so if you still have concerns you can retake the CAST later and share the results with your child's doctor.
What is the goal of the CAST?
The goal is to catch possible signs of autism early, when support makes the biggest difference. It flags children who may benefit from a full evaluation and, if needed, early intervention such as ABA therapy.
Why does identifying autism early matter?
A child's brain is most adaptable in the first few years, so starting support early leads to better long-term outcomes in communication, learning, and everyday skills. An early diagnosis also opens the door to insurance-covered therapy and school accommodations sooner.
Is the CAST a diagnosis?
No. The CAST is a screening tool. Only a qualified professional can diagnose autism through a full evaluation.
Sources
Scott FJ, Baron-Cohen S, Bolton P, Brayne C. The CAST (Childhood Asperger Syndrome Test): preliminary development of a UK screen for mainstream primary-school-age children. Autism. 2002;6(1):9-31.
Williams J, Scott F, Stott C, et al. The CAST (Childhood Asperger Syndrome Test): test accuracy. Autism. 2004;8(3):283-299.
CAST © Autism Research Centre, University of Cambridge. Used with permission.
Reviewed by Samantha Ridout, BCBA
Board Certified Behavior Analyst, Clinical Reviewer at Alpaca Health. Last reviewed July 2026.
Take the first step today
A five-minute screener can bring clarity and open the door to early support. If you have questions or want to talk with someone, the Alpaca Health team is here.
