How to get an autism assessment for your child

Getting an autism assessment is rarely a single conversation. It is a process with gatekeepers, waiting lists and paperwork, and the parents who move through it fastest are usually the ones who understood the process before they started.

This guide covers the whole path, from the first appointment to what happens if you are turned away.

Step 1: Gather evidence before you ask

The most common reason a referral stalls is not that a clinician disagrees with you. It is that there is not enough documented evidence to justify a referral against a stretched service’s threshold.

Spend two to four weeks building a file:

That last item is powerful. A referral letter saying “parent reports concerns” is easy to deprioritise. One saying “positive M-CHAT-R, no response to name across three settings, no pointing to share at 20 months, loss of two words at 18 months” is not.

Our early signs checklist can help you organise what you are seeing into the language clinicians use.

Step 2: Book the right appointment

In the UK. Start with your GP or health visitor. Book a double appointment and say the words: “I would like a referral to the neurodevelopmental pathway for an autism assessment.” For school-aged children, contact the school SENCO in parallel — a school’s supporting evidence carries substantial weight.

In the US. Start with your paediatrician and request a referral to a developmental paediatrician, child psychologist or child psychiatrist. Under 3, you can also contact your state’s Early Intervention programme directly — no doctor’s referral required. From 3 upward, your local school district must evaluate on written parental request, free of charge.

In Australia, Canada, Ireland and elsewhere, the entry point is normally a GP or family doctor referral to a paediatrician or a public child development service.

What to say

Be concrete and unembarrassed:

“I have concerns about my child’s development in two areas — social communication, and repetitive behaviours with sensory differences. I have a four-week log, video, and observations from nursery. I would like a referral for a multidisciplinary autism assessment. If you don’t think a referral is appropriate, could you record that in the notes with the reason?”

That final sentence is the most useful one in this article. Asking for a decision to be documented changes how carefully it is made, and it gives you something to point at later.

Step 3: Expect the waiting list

Waits are long almost everywhere. In parts of the UK, waits from referral to first appointment exceed two years; US waits are commonly six to eighteen months.

Do not treat the wait as dead time.

• Ask to be added to the cancellation list and confirm your availability at short notice.
• Start support now. Speech and language therapy, occupational therapy and educational support do not require a diagnosis.
• Keep logging. Assessors want current information, and a 12-month log is extremely persuasive.
• Request interim support from school. Schools can put accommodations in place immediately, without a diagnosis.
• Check your position every few months and keep a note of who you spoke to and when.

Starting practical strategies during the wait is genuinely worthwhile. Visual schedules, predictable routines, reduced sensory load and sensory breaks help any child who needs them, diagnosis or not.

Step 4: The assessment itself

A good assessment is multidisciplinary — usually a paediatrician or psychologist plus a speech and language therapist, sometimes an occupational therapist — and draws on several sources: a developmental history interview with you, direct observation of your child, and information from school or nursery.

Common tools include the ADOS-2 (a structured play-based observation) and the ADI-R or DISCO (a detailed parent interview). We walk through the whole appointment in what happens at an autism assessment.

Step 5: If you are refused

Rejection is common and is usually procedural, not final.

1. Ask for the reason in writing. “Insufficient evidence” and “does not meet threshold” mean different things and require different responses.
2. Fill the specific gap. If school evidence was missing, get it. If only one setting was described, describe two.
3. Request a review rather than starting over.
4. Go through school instead, if the GP route stalls. A SENCO referral often carries more institutional weight.
5. Escalate. In the UK, PALS and the practice complaints process exist for exactly this. In the US, your school district’s obligation to evaluate on written request is a legal one under IDEA.
6. Ask a second professional. A different GP in the same practice may take a different view.

Private assessments: the honest trade-offs

In favour: weeks rather than years, usually a fuller written report, and often more time with your child.

Against: cost (commonly £1,500–£3,000 in the UK, $2,000–$5,000 in the US); some health services and schools will not automatically accept a private diagnosis; and quality varies.

If you go private, check that the assessment is multidisciplinary, that it uses recognised tools, that it follows national guidance (NICE in the UK), and that the provider will liaise with your school and health service. A single-clinician, single-session diagnosis is more likely to be challenged.

What a diagnosis does and does not do

A diagnosis is a key that opens certain doors: educational support, some therapies, disability benefits in some countries, and workplace and exam accommodations later.

It does not change your child. It changes what other people are obliged to do, and it gives you a framework that makes behaviour legible.

If you have just received a diagnosis, what to do in the first 30 days is the natural next step.