A 20-80 is actually called an 80/20 in mortgage terms. This is a way of purchasing a home with 100% financing, but avoiding what is called "PMI" or Private Mortgage insurance. You get 2 loans...the 1st one is for 80% of the sales price and the 2nd is for 20% of the sales price, thus, you have to pay nothing down. You only pay for the closing costs or