About 90 per cent of the 8,000 kids in Ontario who are wards of the Crown are aged 10 or older.
The province will provide $950 a month — $11,400 a year — to eligible parents who adopt or take legal custody of Crown wards who are at least 10 years old.
The subsidies will be given to families with an annual income of up to $85,000, starting June 15.
The government said the subsidies amount to about 60 per cent of the average cost of foster care.
About 1,000 Crown wards are adopted annually in Ontario, but only 86 of the older kids were adopted last year.