The HOME Plus Program An Arizona mortgage loan is paired with a Arizona down payment assistance grant equal to 4 percent of the mortgage amount. As with all grants, Arizona borrowers will not need to repay the money. Income and purchase restrictions are as follows: the household income of the Arizona borrower may not to exceed $88,340, and the total amount borrowed cannot exceed $353,360. The lowest FICO credit score to qualify is 640. U.S. Military personnel can be granted an additional 1 percent towards the Arizona down payment assistance.