What should I know first?
An autism diagnostic assessment can feel stressful, but preparation helps. Understanding what to expect, what documents to bring, and how to help your child during the process leads to more accurate results and reduces family stress. This guide covers assessment preparation for children of all ages.
Ontario Ministry of Children, Community and Social Services · College of Psychologists and Behaviour Analysts of Ontario · Verified 2026-02-22
Beginner · 1-2 weeks preparation
Quick summary
- Compile Your Child's Developmental History
- Gather Existing Reports and Records
- Write Down Your Observations and Concerns
- Request Input from Teachers and Caregivers
- Prepare Your Child for the Assessment
- Plan for Assessment Day Logistics
Estimated time: 1-2 weeks preparation · Difficulty: beginner
How to Prepare for an Autism Assessment in Ontario · Updated
Steps in this guide
Compile Your Child's Developmental History
Create a written timeline of your child's developmental milestones: when they first smiled, babbled, pointed, walked, spoke first words, and combined words. Note any regressions or plateaus. Include details about pregnancy, birth, and early health. This information is critical for the diagnostician and is often difficult to recall on the spot.
Gather Existing Reports and Records
Collect all previous medical records, developmental assessments, hearing and vision tests, speech-language evaluations, and school reports. If your child attended early intervention programs like Ontario Early Years or EarlyON, request any documentation from those programs. Organize everything chronologically.
Write Down Your Observations and Concerns
Document specific behaviours that concern you across settings: home, school, community outings, and family gatherings. Note communication patterns, social interactions, repetitive behaviours, sensory sensitivities, and daily living skills. Use concrete examples with approximate frequency — diagnosticians find these details invaluable.
Request Input from Teachers and Caregivers
Ask your child's teachers, daycare providers, and other regular caregivers to write a brief description of your child's behaviour in their setting. Some assessment centres provide specific forms for third-party input. Different observers notice different things, and this multi-setting perspective strengthens the assessment.
Prepare Your Child for the Assessment
Explain the assessment in age-appropriate terms. For younger children, you might say "We're going to visit someone who wants to play and talk with you." For older children, explain that the visit helps people understand how they think and learn. Visit the assessment site in advance if possible, or show photos. Plan for comfort items.
Plan for Assessment Day Logistics
Assessments typically last 2-4 hours and may be split across multiple sessions. Ensure your child is well-rested and has eaten. Bring snacks, comfort items, and any fidgets or tools your child uses. Arrange childcare for siblings. Bring your documentation binder. Arrive early to complete intake paperwork.
Sources for this guide
| Source | Record or guidance |
|---|---|
| Ontario Ministry of Children, Community and Social Services | Diagnostic assessment requirements for OAP eligibility (ontario.ca/autism) |
| College of Psychologists and Behaviour Analysts of Ontario | Standards for autism diagnostic assessment and qualified diagnosticians (cpbao.ca) |
Frequently asked questions
Canada's Autism Strategy says families can face long waits and inconsistent diagnostic practices when seeking autism screening and diagnosis. It also says out-of-pocket costs can be burdensome.
In Ontario, autism spectrum disorder can be diagnosed by a registered psychologist, a physician (including developmental pediatricians and psychiatrists), or a multidisciplinary team. For OAP eligibility, the diagnosis must meet specific criteria outlined by the Ministry.
If the assessment does not confirm autism, the diagnostician should explain what they observed and may identify other conditions or recommend further assessment. You can seek a second opinion. Regardless of the outcome, the assessment provides valuable information about your child's strengths and needs.
Where the waitlist stands
Families navigating autism services in Ontario face a documented multi-year wait. Here is the Ontario data — and a two-minute way to push back, when you are ready.
Verified references and sources
Official Government Sources
- [2024]Autism spectrum disorder among children and youth in Canada 2019Public Health Agency of Canada • Government • 2024-03-26
Watchdog Reports
- [2024]Ministry of Children, Community and Social Services: Spending Plan ReviewFinancial Accountability Office of Ontario (FAO) • Watchdog report • 2024-06-05
FOI Records
- [2026]Ontario Autism Program figures as of May 13, 2026 (MCCSS, released under Freedom of Information to the Ontario Autism Coalition; published in the OAC "OAP At A Glance" update, July 2026)Ministry of Children, Community and Social Services (Ontario), obtained by the Ontario Autism Coalition • FOI record • 2026-05-13
Official Organizations
- [2025]Autism Spectrum Disorders Fact Sheet (updated September 17, 2025)World Health Organization (WHO) • Official • 2025-09-17
Peer-Reviewed Research
- [2015]Early Identification of Autism Spectrum Disorder: Recommendations for Practice and ResearchZwaigenbaum L, Bauman ML, Stone WL, et al. (Pediatrics) • Academic • 2015-10-01
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