Home Advantage Down payment Assistance Second Mortgage Program For Washington borrowers who take out a first mortgage loan with Washington State can qualify for Washington down payment and closing cost assistance as well. The assistance comes in the form of a deferred second mortgage at 0 percent. This second loan amount is equal to up to 4 percent of the first loan amount. Payments are not due until mortgage term expires, or the home is sold or refinanced. There is no first time buyer requirement.