Getting your child tested for autism starts with your pediatrician, who can perform an initial screening and then refer you to a specialist for a full diagnostic evaluation. The American Academy of Pediatrics recommends autism-specific screening for all children at their 18-month and 24-month well-child visits, but you can request a screening at any age if you have concerns. The process from first concern to formal diagnosis typically involves two stages: a brief screening, then a comprehensive evaluation by a specialist.
Signs That Prompt Testing
Parents are often the first to notice something is different about their child’s development. The CDC lists specific social and communication behaviors by age that can signal a need for evaluation:
- Not responding to their name by 9 months
- Not showing facial expressions like happy, sad, or surprised by 9 months
- Not playing simple interactive games like pat-a-cake by 12 months
- Using few or no gestures (like waving goodbye) by 12 months
- Not pointing to show you something interesting by 18 months
- Not noticing when others are hurt or upset by 24 months
- Not joining other children in play by 36 months
- Not engaging in pretend play (pretending to be a teacher or superhero) by 48 months
These milestones aren’t pass/fail markers, and missing one doesn’t guarantee an autism diagnosis. But a pattern of delays across several of these areas is a strong reason to move forward with formal screening. You don’t need to wait for your child’s next scheduled visit to raise these concerns.
Step 1: The Initial Screening
The first step is a standardized screening at your child’s pediatrician. This is a short questionnaire, usually filled out by you in the waiting room, that asks about your child’s behavior, communication, and social interactions. The most widely used tool for toddlers is the M-CHAT (Modified Checklist for Autism in Toddlers), which takes about five minutes. Your pediatrician reviews the results and, if the score suggests elevated risk, discusses next steps with you.
A screening is not a diagnosis. It’s a quick filter designed to identify children who need a closer look. If the screening comes back positive, or if your pediatrician shares your concerns even without a formal screening flag, the next step is a referral to a specialist for a comprehensive evaluation.
Step 2: The Diagnostic Evaluation
A full autism evaluation is conducted by a specialist: a developmental-behavioral pediatrician, a child neurologist, a child psychologist, or a neurodevelopmental pediatrician. Some early intervention programs also provide diagnostic assessments. The evaluation is much more involved than the initial screening and typically lasts anywhere from 2 to 8 hours, sometimes spread across multiple appointments.
The gold standard tools used in specialty clinics are the ADOS-2 and the ADI-R. The ADOS-2 is an interactive assessment where a trained clinician observes your child during structured play and social activities, looking for specific patterns in communication, social engagement, and repetitive behaviors. The ADI-R is a detailed interview with you, the parent, that collects a systematic developmental history. The interviewer will ask you to describe specific behaviors in detail across three areas: social interaction, communication, and repetitive or restricted behaviors. Both current behaviors and lifetime patterns are scored.
These aren’t simple checklists. Administering them requires specialized training, and responses require clinical interpretation. Not every evaluator uses both tools, and some clinics use alternative validated instruments, but the goal is the same: to determine whether your child meets the diagnostic criteria for autism spectrum disorder across two core domains (social communication difficulties and restricted or repetitive behaviors).
Who Can Make the Diagnosis
Only certain professionals can provide a formal medical diagnosis of autism. These include developmental-behavioral pediatricians, child neurologists, child psychiatrists, licensed clinical psychologists with specialized training, and in some cases geneticists. Your regular pediatrician can screen and refer but typically won’t make the final diagnosis themselves.
When choosing a provider, verify they have specific experience with autism evaluations in children. A general psychologist or neurologist may not have the specialized training needed for the assessment tools or the clinical judgment required to interpret borderline cases.
Expect a Wait
One of the biggest frustrations parents face is the wait time for a specialist evaluation. A CMS survey of autism centers across the U.S. found that nearly two-thirds of centers had wait times longer than four months. About 31% of centers reported waits of four to six months, and roughly 14% had waits exceeding one year or had stopped accepting new referrals entirely. Only 13% of centers could see a child within four weeks.
If you’re facing a long wait, there are a few things you can do. Get on multiple waitlists at once. Ask to be placed on a cancellation list for earlier openings. Contact your state’s early intervention program (for children under 3) or your local school district (for children 3 and older), as these programs can begin providing services based on developmental delay without requiring a formal autism diagnosis first. Starting support early matters more than waiting for a perfect diagnostic label.
What to Bring to the Evaluation
Come prepared to give a thorough developmental history. The clinician will want to know when your child hit major milestones (first words, first steps, first two-word phrases) and when you first noticed concerns. Bring any records from your pediatrician, including past screening results, developmental notes, and reports from daycare or preschool teachers who have observed your child’s behavior in a group setting.
Many parents find it helpful to bring short video clips of the behaviors that concern them, since children don’t always display their typical patterns in an unfamiliar clinical setting. Videos of your child at home, at a playground, or during family gatherings can give the evaluator a more complete picture. Write down specific examples of behaviors you’ve observed, with approximate dates if possible, so you can recall details clearly during a long interview.
Medical Diagnosis vs. School Evaluation
These are two different processes that serve different purposes, and one does not replace the other. A medical diagnosis is made by a clinician using the criteria in the DSM (the standard diagnostic manual). Under the medical model, a diagnosis alone is usually enough to access treatment like speech therapy or behavioral therapy through your insurance.
A school-based evaluation, by contrast, determines whether your child qualifies for special education services under federal law (IDEA). A team of school professionals and parents must find that the child has one of 14 recognized disabilities and that the disability interferes with learning enough to require special services. Because of this extra requirement, it is possible, and not uncommon, for a child to have a medical autism diagnosis but be found ineligible for special education because they are performing adequately in school.
The reverse is also true: a school can identify a child under the autism category for an IEP without a medical diagnosis. If you want both access to therapies through insurance and school-based accommodations, you may need to pursue both processes separately.
Navigating Insurance Coverage
Most states now have laws requiring insurance companies to cover autism diagnosis and treatment. However, coverage typically comes with conditions. In most states, covered treatment must be prescribed by a physician or psychologist as part of a documented treatment plan. Some insurers require pre-authorization before the evaluation, and many apply standard cost-sharing like copays and deductibles.
Before scheduling an evaluation, call your insurance company and ask three specific questions: whether the evaluating provider is in-network, whether you need a referral or pre-authorization, and what your out-of-pocket costs will be. If the specialist your pediatrician recommends is out of network, ask your insurer about out-of-network exceptions, especially if in-network providers have wait times exceeding several months. Document these calls, including the representative’s name and any reference numbers.
After the Diagnosis
Once your child receives a diagnosis, the evaluating clinician will typically recommend specific therapies based on your child’s age, strengths, and areas of need. Common next steps include speech-language therapy for communication challenges, occupational therapy for sensory or motor difficulties, and applied behavior analysis (ABA) for building social and adaptive skills. For children under 3, your state’s early intervention program coordinates these services, often at no cost to the family. For children 3 and older, services shift to your local school district, though you can also pursue private therapy through insurance.
It’s also worth checking for co-occurring conditions. Many autistic children also experience anxiety, sleep difficulties, feeding challenges, or attention issues. These aren’t always assessed during the autism evaluation itself, so bring them up with your pediatrician separately. Getting a complete picture of your child’s needs means they get the right combination of support from the start.