Over the first three years (36 months) of ownership, the down payment assistance is forgiven 1/36th each month. After the third anniversary (36 months) of closing, you will not have to repay any portion of the assistance you received. If you sell or refinance before the 36 months is up, you must pay back the remaining portion of the loan.
Here is an example: A borrower received $10,000 in assistance and 28 months after closing they decide to refinance their home. They are going to owe back a portion of the assistance they received. Remember, the assistance is forgiven at 1/36th per month which means, in month 28 after closing, $7,777 of the $10,000 amount has been forgiven. So, the borrower will owe $2,223 when they refinance or sell their home.