When purchasing a home, a 20% down payment is typically the standard. The lender's only liability is often just the remainder between the home value and the balance remaining on the loan, so the 20% adds a nice cushion against the costs of foreclosure, selling the home again, and natural value fluctuations in the event a purchaser doesn't pay. During the recent mortgage boom of the last decade, it became common to see lenders reducing down payments to 10, 5, 3 or sometimes 0 percent. A lender is able to handle the additional risk of the small down payment with Private Mortgage Insurance or PMI. PMI guards the lender in the event a borrower doesn't pay on the loan and the market price of the house is lower than what is owed on the loan. PMI can be pricey to a borrower in that the $40-$50 a month per $100,000 borrowed is rolled into the mortgage monthly payment and frequently isn't even tax deductible. Different from a piggyback loan where the lender absorbs all the deficits, PMI is money-making for the lender because they acquire the money, and they receive payment if the borrower defaults.