How to Get Autism Diagnosis Australia: Step-by-Step Guide

What is an ASD assessment in Australia?

An ASD assessment is a structured process in which trained clinicians look at development, communication, behaviour and daily functioning. ASD diagnosis is the outcome when the clinicians conclude the person meets the criteria for autism spectrum disorder.

Australian practice follows the National Guideline, which launched in 2018. The second edition (2023) has 66 Recommendations and was approved by the NHMRC on 8 December 2023 for five years (Autism CRC).

People often ask when autism was first diagnosed. Autism has been recognised for many decades, and the criteria have changed over time, so it helps to ask which criteria a clinician uses now. For the criteria clinicians use now, see autism diagnostic criteria in Australia, and for a plain definition see the autism definition.

Assessments for autism spectrum disorder: who can diagnose

The 2023 Guideline sets out who should lead a Diagnostic Evaluation, so ask about the clinician’s qualifications before you book. Our guide on who can diagnose autism in Australia has more detail.

So, can an OT diagnose autism? Under the Guideline an occupational therapist can contribute to a team evaluation, but the lead roles above belong to medical practitioners and psychologists.

TQN Care support workers help with personal care, community access, respite and help around the home across Sydney, Melbourne and surrounding areas (NSW & VIC). Tell us what you need and we will call you back.

How to get autism diagnosis Australia: step by step

These general steps apply to families and adults, though the details and waiting times vary by service.

1. 1Write down what you have noticed. Include examples from home, school or work, with dates, so the clinician sees the pattern.
2. 2See your GP for a referral. Ask for a referral to a paediatrician, psychiatrist or psychologist who assesses autism.
3. 3Join the waiting list early. Public services can have long waiting lists, so ask to be added while you consider private options.
4. 4Complete the Comprehensive Needs Assessment. This covers an assessment of functioning and a medical evaluation.
5. 5Attend the Diagnostic Evaluation. It happens if autism is suggested, and you will discuss the findings afterwards.
6. 6Ask for a written report and referrals. Keep the report, as schools, therapists or the NDIS may ask to see evidence.

Not sure where to start? Our guides to the autism test in Australia and autism screening tests explain how screening differs from diagnosis.

ASD assessment for children and autism assessment for a child

Autism can be diagnosed between 12 and 18 months, but diagnosis is usually from around 2 years of age (Raising Children Network). If you have concerns, you do not need to wait until school age to ask your GP about an assessment.

• Ask your child health nurse or GP about developmental concerns as soon as you notice them, including at toddler checks.
• Read about testing for autism in toddlers to understand what a screening questionnaire can and cannot tell you.
• For older children and teens, see the autism test for teens and what a clinician will look at.
• Ask about Medicare item 135, which covers a paediatrician attendance of at least 45 minutes where a complex neurodevelopmental disorder such as autism is diagnosed and a treatment plan developed, for patients under 25, once per lifetime.
• Bring school reports, speech or OT reports and short videos of your child in everyday settings.

Autism assessment for adults and women

Adults can be assessed too, and the same starting point applies: talk to your GP about a referral. Ask each service whether it assesses adults.

• Read our guide to adult autism diagnosis for what the process involves.
• Learn about the autism test for adults in Australia and how clinicians use interviews rather than quizzes.
• See the female autism test guide for why presentations can differ.
• Medicare item 135 applies to patients under 25, so adults over that age should ask about other pathways and costs.
• Ask whether telehealth is offered; our guide to autism assessment by telehealth explains the options.

Psychology, cognitive and OT assessment for autism

A full assessment can include several parts. A psychology autism assessment, a cognitive assessment for autism and an OT assessment for autism each answer a different question.

Ask the clinician which parts are included in the quoted price. A functional capacity assessment is useful evidence, but it is not the same as a diagnosis.

ASD assessment cost and the gap when you get autism diagnosis in Australia

Public autism assessments are offered at no cost to families but many services have long waiting lists. Private assessments can be expensive, with Medicare rebates for some sessions (Raising Children Network).

• Ask for the total fee, how much is rebated and what the ASD assessment gap will be before you book.
• Medicare item 135 has a schedule fee of $320.55 (updated 1 July 2026), which is the fee set, not necessarily what you pay (MBS Online).
• Compare public and private waiting times, and consider joining a public list while you wait.
• See free and low-cost autism assessment in Australia and ADHD assessment cost for price comparisons.

Autism tests, quizzes and screening

Many people start online. These tools can prompt reflection, but only a qualified professional can assess autism.

• Do I have autism quizzes can prompt reflection but are not diagnostic.
• Free autism tests are screening tools; ask a clinician to explain any result.
• The autism spectrum quotient (AQ) is a questionnaire, not a diagnosis.
• If you suspect ADHD as well, read about the ADHD and autism assessment; the Australian ADHD Guideline found children and adolescents with autism have a significantly higher risk of ADHD.

How to get autism diagnosis Australia and the NDIS

If you meet the NDIS access requirements, the NDIS may fund supports, and diagnostic and functional evidence is part of that. Read our guide to autism funding through the NDIS.

• Keep your diagnostic report, therapy reports and any functional capacity assessment together in one folder.
• Explore whether autism is a disability under Australian law and the NDIS.
• Check the current NDIA access requirements before you apply.
• Ask Autism Connect on 1300 308 699 for free advice about supports while you wait.

When to talk to a GP or specialist

• Your child is not meeting developmental milestones, or you have concerns about communication, play or sensory responses.
• A teacher, childcare worker or health professional has suggested an assessment.
• You are an adult who has long wondered whether you are autistic and want proper answers.
• You are on a waiting list and want to know what support you can access in the meantime.
• You want to compare ADHD-related costs, such as how much ADHD medication costs, and ADHD assessment pathways.

Call 000 in an emergency. If you feel overwhelmed, Lifeline is on 13 11 14. For ADHD, see how to get an ADHD diagnosis.

TQN Care support workers help with personal care, community access, respite and help around the home across Sydney, Melbourne and surrounding areas (NSW & VIC). Tell us what you need and we will call you back.

Your next step

If you are starting this process, begin with a GP appointment and a page of examples. While you wait, practical help can ease daily routines for the person at the centre. TQN Care support workers help with personal care, community access, respite and help around the home, and we are happy to talk through your needs. See our NDIS services or make a referral.