The 10/20 Mortgage is a typically a Fannie Mae mortgage product. This particular mortgage allows the borrower to pay only the interest on the mortgage for the first 10 years and then for the final 20 years of the loan it they pay off the principal. With a 10/20 mortgage the interest rate remains he same throughout the loan - and the payment only changes once, offering a bit of security along with a low payment. (Also referred to as the 10-20 Mortgage).

Bankapedia's Take

With the ARM and Interest Only Mortgage coming under severe scrutiny during the Subprime Meltdown the 10/20 offered a creative way to keep the payment all the while allowing the borrower to sleep at night. Like most interest only loans, principal payments are still allowed. Additional rates on 10/20's are nearly identical to the 30 yr fixed. Expect to hear more and more about the 10/20 post 2007.