Autism can be identified as early as 18-24 months. Knowing the signs helps parents act sooner and access support faster.
Autism signs in toddlers vary significantly from child to child — there is no single profile. Some children show clear signs very early; others develop typically until 18-24 months and then lose skills they previously had (called regression). The following age-linked milestones can help parents identify when to seek assessment:
By 12 months: not babbling, not pointing or waving, not responding to their name, limited or fleeting eye contact. By 16 months: no single words. By 18-24 months: the M-CHAT-R screening is administered in Canada; signs at this stage may include not using two-word phrases, not imitating actions, not showing interest in other children, and repetitive movements like hand-flapping or spinning. By 36 months: limited pretend play, difficulty with transitions, and very focused interests in specific objects or topics.
Remember: all autistic children are different. Some may have excellent verbal language but significant sensory and social communication differences. If you have concerns, act on them — developmental assessments can only help, and a negative result provides valuable reassurance.
The Modified Checklist for Autism in Toddlers, Revised (M-CHAT-R/F) is a validated screening tool completed by parents or caregivers at the 18-month and 24-month well-child visits in Canada. It asks 20 yes/no questions about your child's behavior — things like whether your child makes eye contact, responds to their name, and points to show you things they are interested in.
A score above the threshold prompts a follow-up interview and, if concerns remain, a referral for full diagnostic assessment. The M-CHAT-R is a screening tool, not a diagnostic test: a positive screen does not mean your child has autism, and a negative screen does not rule it out. Parent concern, even in the context of a negative M-CHAT-R, should still be taken seriously and monitored.
If your child's doctor has not administered the M-CHAT-R at their 18-month or 24-month visit, you can ask for it specifically. The screening is publicly available and takes about five minutes.
If you have concerns about your toddler's development, do not wait for a scheduled check-up. Call your family doctor or pediatrician and request an appointment specifically to discuss developmental concerns. Write down the specific behaviors that concern you — dates, frequency, specific examples — before the appointment. This documentation helps the clinician assess the situation accurately.
Ask your doctor specifically for a developmental referral. In Ontario, this will typically be to a developmental pediatrician. Some regions have dedicated pediatric autism assessment clinics. If your doctor is not responsive to your concerns, you have the right to seek a second opinion or request a specialist referral directly.
While waiting for assessment, you can access some services without a formal diagnosis. Speech-language pathology services through your local children's treatment centre, publicly funded preschool programming, and community play groups can support your child's development in the interim.
In Ontario, the publicly funded pathway to autism assessment runs through the OAP (Ontario Autism Program). After a referral from your doctor, your child will be placed on a waitlist for assessment. Current waitlists for publicly funded assessments in Ontario can be one to three years or longer depending on your region. Once diagnosed, your child can be registered with the OAP for funded services — though OAP service waitlists are also lengthy.
Private assessment is available in Ontario and across Canada. Costs vary from approximately $2,000 to $5,000 depending on the provider, location, and scope of assessment. A private assessment can typically be completed within weeks rather than years. The resulting diagnosis is equally valid for OAP registration and school board identification purposes.
Other provinces have varying access and timelines. British Columbia, Alberta, and Quebec each have their own autism program structures. Families outside Ontario should contact their provincial autism organization for province-specific guidance.
Early signs of autism in toddlers may include: not responding to their name by 12 months; limited or absent eye contact; not pointing to share interest (like pointing at a dog) by 12 months; no babbling by 12 months; no single words by 16 months; no two-word phrases by 24 months; repetitive movements (hand-flapping, rocking, spinning); intense interest in parts of objects (like spinning wheels on a toy car); unusual reactions to sensory input; and limited imitation of others. Signs vary widely and not every autistic child shows all signs.
Autism can be reliably diagnosed as early as 18-24 months by experienced clinicians, though diagnosis is often made later. Many children are not diagnosed until preschool or school age. Some people, particularly women, girls, and those who mask effectively, are not diagnosed until adolescence or adulthood. Earlier diagnosis is generally associated with better access to early intervention, but a diagnosis at any age is valid and valuable.
The Modified Checklist for Autism in Toddlers, Revised (M-CHAT-R/F) is a validated developmental screening tool used at the 18-month and 24-month well-child visits in Canada. It consists of 20 questions answered by parents about their child's development and behavior. A positive screen indicates a higher likelihood of autism and prompts referral for a full diagnostic assessment. The M-CHAT-R is a screening tool, not a diagnostic test — a positive result does not mean a child has autism.
If you are concerned about your toddler's development, speak to your family doctor or pediatrician at your next visit — or call to make an appointment specifically to discuss your concerns. Bring a list of specific observations. Ask for a developmental screening (M-CHAT-R) and, if indicated, a referral to a developmental pediatrician or autism assessment clinic. You do not need to wait for a scheduled check-up — any concern about your child's development warrants a conversation with your doctor.
In Ontario, the pathway to autism assessment for toddlers typically begins with a referral from your family doctor or pediatrician to a developmental pediatrician or an autism assessment clinic. Public assessments through the Ontario Autism Program (OAP) involve significant waitlists. Private assessments are available and can be completed faster but cost between $2,000 and $5,000 depending on the provider and location. Once your child has a diagnosis, you can register with the OAP to access funded services — though OAP waitlists are currently several years long.
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Verified Facts
1 in 50 — According to the 2019 Canadian Health Survey on Children and Youth, about children and youth aged 1 to 17 in Canada had an autism diagnosis
Evidence supports autism screening and intervention commencing in the first 2 years of life — earlier identification directly enables earlier intervention during the highest neural plasticity window
WHO recommends accessible, community-based early interventions for children with autism — timely evidence-based psychosocial interventions improve communication and social engagement
87,692 — children are registered in the Ontario Autism Program
23.1% — 23,875 children enrolled in Core Clinical Services; 20,293 have active funding agreements ()
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