If your down payment on a home is less than 20 percent of the appraised value or sale price, you must obtain private mortgage insurance, known as PMI, with your lender. This will enable you to obtain a mortgage with a lower down payment because your lender is now protected against any default on the loan.

PMI charges vary depending on the size of the down payment and the loan, but they typically amount to about one-half of one percent of the loan, according to the Mortgage Bankers Association of America. Mortgage insurance premiums are not tax deductible.