Direct answer
Quick AnswerThe primary autism screening tool used in Ontario well-baby visits is the M-CHAT-R/F (Modified Checklist for Autism in Toddlers, Revised with Follow-Up), administered at 18 and 24 months. The 18-Month Enhanced Well-Baby Visit in Ontario also includes structured observation and parent interview. Screening tools identify risk — a positive screen requires referral for full diagnostic assessment by a qualified professional.
Start with the short answer, then reveal deeper context where helpful.
Screening tools like the M-CHAT-R/F are designed to identify children who may be at risk for autism — they are not diagnostic. A positive screen means your child should be referred for a comprehensive diagnostic assessment. A negative screen does not definitively rule out autism, especially in girls and children who may not yet show observable differences at 18 months.
Screening tools like the M-CHAT-R/F are designed to identify children who may be at risk for autism — they are not diagnostic. A positive screen means your child should be referred for a comprehensive diagnostic assessment. A negative screen does not definitively rule out autism, especially in girls and children who may not yet show observable differences at 18 months.
Ontario's 18-month enhanced well-baby visit includes developmental surveillance beyond the M-CHAT. Your pediatrician or family doctor should be monitoring developmental milestones and referring for assessment if concerns arise at any age.
Research
Robins et al. (2014), "Validation of the M-CHAT-R/F," Pediatrics, 133(1), 37-45
MCCSS
Ontario's 18-Month Enhanced Well-Baby Visit Guide
In Ontario, autism can be diagnosed by psychologists, developmental pediatricians, psychiatrists, and some pediatricians. Learn the pathways and costs.
A comprehensive autism assessment includes developmental history, standardized testing (ADOS-2, ADI-R), cognitive assessment, and clinical observation.
OHIP-covered autism assessments take 12-24 months to access plus 4-8 hours of testing. Private assessments: 2-8 week wait, same testing duration.
Commitment to Accuracy: Our data is verified against official government reports (FAO, MCCSS), peer-reviewed scientific literature, and accessible public records. Last updated: March 24, 2026.
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