The real number is a subtraction.

Before the 2019 OAP redesign, approximately 23,000 children were registered. The 2019 reform changed the program structure, eliminated the former Intensive Behavioural Intervention (IBI) tier, and opened a new Core Funding Agreement pathway intended to reduce wait times. Instead, registrations grew from approximately 23,000 to 91,974 by May 2026, an increase of ~300%.

CBC News, using FOI data covering 18 months of bi-weekly OAP progress reports (June 2024 through January 2026), documented that the waitlist jumped approximately 21% since mid-2024 alone. During one two-week period last summer, the number of funded children dropped by 151 while 456 new children registered, a net addition of over 600 to the unfunded group in a single reporting period.

Registration alone does not establish that a child has an active Core Funding Agreement or is receiving therapy. The progress report records administrative stages; it does not report therapy hours, privately paid care, other OAP supports, or services outside the OAP.

The World Health Organization says timely access to evidence-based psychosocial interventions can improve communication and social skills. The government progress reports do not publish a province-wide average OAP wait or comparable regional averages. The Ontario Autism Coalition's July 2026 community update provides an invitation-cohort signal, not an official average or individual forecast.

Ontario allocated $965M to the OAP in the 2026-27 budget, a significant increase from $779M the prior year. However, the Financial Accountability Office's 2020 analysis estimated $1.35B would be needed annually to serve all eligible children at 2018–19 service levels. That estimate was based on approximately 40,700 children. With 91,974 children now registered, the true cost to eliminate the backlog is substantially higher.

The FAO's 2023–24 Spending Plan Review reported total OAP spending of approximately $600 million for fiscal year 2023–24, serving 10,142 children, roughly $59,200 per child served. Multiplying that historical average by the current number without an active agreement produces an illustrative figure, not a government cost estimate or a forecast of the funding required for each person.

From January 7 to May 13, 2026, OAP registrations increased by an average of approximately 918 new registrations per month. Active Core Funding Agreements increased at a slower measured rate. Over that interval, the number registered without an active agreement increased by an average of approximately 907 children per month. Reusing those rates produces an estimate of approximately 77,612 by December 2026 (straight-line projection if current rates hold) and 88,496 by December 2027 (projection), an ETWO projection, not a government forecast.

To simply stop the waitlist from growing, the province would need to issue new Core Funding Agreements at the same rate children register, approximately 918 per month. To reduce the existing administrative gap within five years while keeping up with new registrations, an illustrative model would require approximately 2,106 new active agreements per month. This is arithmetic based on constant-rate assumptions, not a government delivery plan.

The 91,974 figure counts only children who have completed an autism diagnosis and registered with the OAP. Several groups are not counted:

• Children awaiting diagnosis. Before a child can register with the OAP, they need an autism diagnosis. Ontario does not publish a province-wide diagnostic waitlist. A Freedom of Information request to Trillium Health Partners revealed 6,113 children waiting for diagnosis at five diagnostic hubs in March 2024. The province-wide total is unknown; the five-hub figure must not be extrapolated to Ontario.
• Children who aged out. Children who turn 18 are no longer eligible for the OAP. The government does not publish how many children aged out of the registered count while lacking an active agreement. The source does not report whether they received services before aging out, so an access outcome cannot be inferred.
• Undiagnosed children. The Public Health Agency of Canada reported an autism prevalence of 1 in 50 children (2019). A 2025 Frontiers study found a 2.1% prevalence rate specifically in Ontario. Not all children with autism are diagnosed or registered with the OAP. The number of undiagnosed or unregistered children with autism in Ontario is not tracked.