Ontario publishes Core Clinical Services amounts by four age bands, and within each band by the support level assigned in your Determination of Needs. Up to age 3, the amount is $10,900 for limited or moderate needs, or $65,000 for extensive needs. Ages 4 to 9 have four levels: $8,900 limited, $24,500 moderate, $36,800 moderate-plus, and $65,000 extensive.
Ages 10 to 14 are $7,600 limited, $18,800 moderate, and $41,400 extensive. Ages 15 to 17 are $6,600 limited, $18,300 moderate, and $31,900 extensive. Two things follow from this: amounts step down as a child gets older, and support level matters more than age — an extensive-needs 4-year-old is funded at $65,000 while a limited-needs 4-year-old is funded at $8,900.
At 18, OAP childhood funding ends outright. There is no OAP amount for adults; families apply to Developmental Services Ontario for adult supports instead.