Testing a child for autism is a multi-step process that typically begins with a developmental screening at your pediatrician’s office and, if concerns arise, moves to a comprehensive evaluation by a specialist. By age 2, an experienced professional can make a diagnosis that’s considered clinically reliable, so starting early matters. Here’s what the process looks like from start to finish, what it costs, and how to navigate the wait.
Screening: The First Step
Most children are first screened for autism during routine well-child visits. The American Academy of Pediatrics recommends universal screening at 18 and 24 months. These screenings are brief questionnaires, usually filled out by parents in the waiting room, that flag potential signs of autism. A screening isn’t a diagnosis. It simply tells your pediatrician whether a more thorough evaluation is warranted.
If your child’s screening raises concerns, or if you’ve noticed signs at home that worry you, your pediatrician will refer you to a specialist for a formal diagnostic evaluation. You don’t need to wait for a screening to request a referral. If something feels off to you, say so.
What a Formal Evaluation Looks Like
A comprehensive autism evaluation is most accurately conducted by a multidisciplinary team, often led by a developmental-behavioral pediatrician, child psychologist, or child psychiatrist. The team may also include a speech-language pathologist and an occupational therapist. The evaluation pulls together information from multiple sources: direct observation of your child, a structured interview with you about your child’s development and behavior, and a review of your family and medical history.
Two standardized tools are commonly used during evaluations. The first is an observation-based assessment where a clinician interacts with your child using specific activities designed to reveal how they communicate, play, and respond socially. The second is a structured parent interview that walks through your child’s developmental history in detail, covering social skills, communication patterns, and repetitive behaviors. Both require specialized training to administer and score, and neither one alone is enough to make a diagnosis. Clinicians use these tools alongside their own clinical judgment to reach a conclusion.
The evaluation itself usually takes several hours, sometimes spread across two or more appointments. Your child won’t experience anything painful or invasive. Expect play-based activities, conversations, and tasks that feel more like structured playtime than a medical test.
What Clinicians Are Looking For
A formal autism diagnosis requires that a child show persistent difficulties in two core areas. The first is social communication and interaction, which includes things like limited back-and-forth conversation, unusual eye contact or body language, and difficulty forming friendships or engaging in imaginative play with peers. A child must show challenges in all three of those social communication areas.
The second core area is restricted or repetitive behaviors. A child needs to show at least two of these four patterns:
- Repetitive movements or speech, such as lining up toys, flipping objects, or echoing phrases
- Rigid routines, like extreme distress over small changes, needing to take the same route, or eating the same food every day
- Intensely focused interests that are unusual in their strength or subject matter
- Sensory differences, such as seeming indifferent to pain, reacting strongly to certain sounds or textures, or being fascinated by lights and movement
If a child meets these criteria, the diagnosis also includes a support level. Level 1 means “requiring support,” Level 2 means “requiring substantial support,” and Level 3 means “requiring very substantial support.” These levels help guide the type and intensity of services your child receives.
Genetic Testing After Diagnosis
Genetic testing is recommended for all children who receive an autism diagnosis. The standard tests are a chromosomal microarray and a fragile X test. These don’t diagnose autism itself but can identify underlying genetic conditions that may be contributing. Research from Baylor College of Medicine found that no specific developmental or medical characteristic predicts which children will have a positive genetic finding, which is why the recommendation applies to every child on the spectrum, not just those with certain traits.
School Evaluations Are Not the Same
Many parents assume that a school evaluation and a medical diagnosis are interchangeable. They’re not. A medical diagnosis comes from a doctor or psychologist using clinical criteria. A school evaluation determines whether your child qualifies for special education services under federal law. The school team, which includes educators and specialists along with parents, must find that autism symptoms specifically interfere with learning and that the child needs special services to make academic progress.
This means a child can have a medical diagnosis of autism and still be found ineligible for school-based services if the team determines they’re managing academically. It also means the reverse is possible: a school can identify a child as eligible for services under the autism category without a formal medical diagnosis. If you want access to both medical treatments (like behavioral therapy) and school supports, pursuing both evaluations is often the smartest move.
How Long You’ll Wait
This is the frustrating part. A survey of autism diagnostic centers across the U.S. by the Centers for Medicare and Medicaid Services found that nearly two-thirds of centers had wait times longer than four months. About 15% reported waits of over a year, and some had stopped accepting new referrals entirely. Wait times ranged from under four weeks to well over a year depending on location and demand.
These delays matter because early intervention during the first few years of life, when the brain is most adaptable, produces the strongest outcomes. If you’re facing a long wait at one center, ask to be placed on multiple waitlists simultaneously. Some families also pursue evaluations through telehealth or travel to centers in less saturated areas to shorten the timeline.
What It Costs
The cost of an autism evaluation varies widely depending on who conducts it, where you live, and how comprehensive the assessment is. A basic diagnostic evaluation typically runs $250 to $2,500 out of pocket. A comprehensive evaluation that includes cognitive, language, and adaptive behavior testing can cost $500 to $3,000, with some formal diagnostic assessments reaching up to $5,000.
Insurance coverage depends on your plan. Many private insurers cover evaluations when they’re deemed medically necessary, though you may need documentation from your pediatrician and prior authorization. Medicaid is required by federal law to cover medically necessary diagnostic testing, and for children under 21, Medicaid guarantees access to screening, diagnosis, and treatment services through a program called EPSDT. Coverage details vary by state, so checking with your specific plan before scheduling is worth the phone call.
If you can’t afford a private evaluation, university-affiliated clinics and children’s hospitals sometimes offer lower-cost assessments. Your state’s early intervention program (for children under 3) or school district (for children 3 and older) can also conduct evaluations at no cost to you, though these may focus more on eligibility for services than on a clinical diagnosis.
How to Get Started
The most direct path is to contact your child’s pediatrician and request a referral to a developmental specialist. Be specific about the behaviors you’ve observed: note when they happen, how often, and how they compare to what you see in same-age peers. If your pediatrician is dismissive and your gut says something is worth exploring, you’re within your rights to seek a referral elsewhere or contact a diagnostic center directly.
For children under 3, you can also self-refer to your state’s early intervention program without a doctor’s referral. For children 3 and older, you can request a free evaluation through your local school district by putting the request in writing to the principal or director of special education. The district is legally required to respond within a set timeframe, which varies by state but is typically 60 days.