On a conventional mortgage, when your down payment is less than 20% of the purchase price of the home mortgage lenders usually require you get Private Mortgage Insurance (PMI) to protect them in case you default on your mortgage. Sometimes you may need to pay up to 1-year’s worth of PMI premiums at closing which can cost several hundred dollars. The best way to avoid this extra expense is to make a 20% down payment, or ask about other loan program options.