I’ve lurked a long time and thought I should throw in my two cents worth. A good way to pay down the mortgage is to pay the next months principle along with this months payment. Initially, the payment is comprised of mostly interest with little principle, the extra is not a big stretch. As the years go by, the principal payment increases but theoretically so does your income. You can chose to make the extra payment or not each month. If you do it this way, its a 15 year mortgage.