A conventional mortgage loan requires a 20% down payment. If you are a first-time homebuyer however, saving up tens of thousands of dollars can seem like an impossible task. Of course, there are loan programs, like FHA mortgages, that allow for low down payments, but they often have stricter requirements. For some of those programs, you may have to pay higher interest rates, have better credit scores, or pay higher mortgage insurance fees.  Fortunately, there is a little-known mortgage loan that requires no down payment and minimal fees: the USDA loan.