New here? Start with our 2-minute guide to OAP registration , no sign-up required.
Comorbidity guide
Approximately 30-Rate unavailable; the cited research populations and methods differ of autistic individuals also have an intellectual disability (ID), defined as an IQ below 70 with concurrent deficits in adaptive functioning. This dual diagnosis has profound implications for service planning, educational placement, transition to adulthood, and long-term residential and employment support. In Ontario, individuals with dual ASD-ID may access services through both the autism program stream and the developmental services stream, but navigating both systems requires careful coordination.
These guides sit within Ontario's autism funding system. The May 13, 2026 OAP administrative snapshot reports 91,974 registered children. A separate Ontario Autism Coalition July 2026 community-reported invitation cohort describes a five-year-plus signal; Ontario does not publish an official average wait.
The reported co-occurrence rate of intellectual disability in autism has changed over time as diagnostic practices have evolved. Earlier studies reported rates of 50-Rate unavailable; the cited research populations and methods differ, but recent population-based studies using broader autism diagnostic criteria find rates of 30-Rate unavailable; the cited research populations and methods differ. A 2021 meta-analysis by Postorino et al. confirmed a pooled prevalence of approximately Rate unavailable; the cited research populations and methods differ across 38 studies.
Cognitive assessment in autistic individuals requires instruments validated for this population. Standard IQ tests may underestimate abilities due to the influence of language delays, social demands of the testing situation, and attentional differences. Ontario clinicians increasingly use non-verbal IQ measures (e.g., Leiter-3) and adaptive behaviour assessments (Vineland-3) to provide a more accurate picture.
In Ontario, individuals with dual ASD-ID can access services through multiple pathways. The Ontario Autism Program provides clinical services during childhood. Developmental Services Ontario (DSO) provides the gateway to adult developmental services including residential supports, day programs, and Passport funding for community participation.
Eligibility for adult developmental services requires a Developmental Services Ontario application. Families often start before age 18 to reduce gaps. Confirm age rules, required assessments, and eligibility criteria with DSO.
The Surrey Place Dual Diagnosis Program in Toronto and regional dual diagnosis justice programs serve individuals with complex co-occurring presentations. Community Networks of Specialized Care provide consultation and support for challenging situations across Ontario.
Postorino, V. et al.
Intellectual Disability in Autism Spectrum Disorder: Updated Meta-Analysis. European Journal of Psychiatry, 2021; 35(3):187-198
Developmental Services Ontario
Eligibility and application guidelines for adult developmental services, 2024
Developmental Services Ontario requires documentation of a developmental disability. An autism diagnosis alone may not qualify. Ask DSO what assessments are required and when to apply.
At 18, Ontario Autism Program eligibility ends and adult supports may become the main pathway. Ask Developmental Services Ontario about Passport funding, residential support, and ODSP referrals.
Standard IQ tests may underestimate autistic children's abilities due to language demands, social testing conditions, and attentional differences. Request that the assessor use autism-appropriate instruments including non-verbal IQ measures and adaptive behaviour assessments. Multiple assessment sessions may be needed for accurate results.
Next Steps
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.
Related Resources
How long does autism diagnosis take in Ontario?
VerifiedBefore joining the OAP waitlist, Ontario diagnostic waitlists average 12–24 months at public hospitals. This pre-waitlist delay means total time from first concern to therapy often exceeds 5–7 years, an invisible bottleneck in official statistics.
Source: Ontario Autism Program [OAP] · Verify Link
Is private autism assessment faster in Ontario?
VerifiedPrivate autism assessments cost $2,500–$4,000 but reduce wait times from years to weeks. Many families face the choice of paying out-of-pocket to access the OAP sooner or waiting while their child misses the critical early intervention window.
Source: Ontario Autism Program [OAP] · Verify Link
How long do families wait for Ontario autism services?
VerifiedOntario autism wait times for core clinical services now exceed 5+ years (Ontario Autism Coalition, July 2026). Funding invitations are currently reaching families who registered in August 2021 (Ontario Autism Coalition, July 2026 (reported from community intake)). This delay far exceeds the sensitive early intervention window recommended by developmental specialists.
Source: MCCSS FOI via OAC · Mar 2026, FAO Report 2024 · Verify Link
How many children are on the Ontario autism waitlist in 2026?
VerifiedAs of May 13, 2026, 91,974 children are registered with the Ontario Autism Program. However, only 20,711 (22.5%) have an active Core Funding Agreement. This represents ~300% growth in registrations since 2019, with 71,263 children still waiting for essential funding.
Source: MCCSS FOI via OAC · Mar 2026, FAO Report 2024 · Verify Link