A mortgage is high ratio if the borrower's down payment is less than 20% of the property value. A high ratio mortgage requires mortgage default insurance.
CMHC, Genworth Financial Canada, Canada Guaranty
The Canadian government promotes home ownership by guaranteeing insurance that covers lenders in the event that a borrower defaults on their high-ratio mortgage.
In Canada, there are 3 main providers of insurance for high-ratio mortgages: Canada Mortgage and Housing Corporation (CMHC), Genworth Financial Canada and Canada Guaranty.