The Federal Truth in Lending law requires that all financial institutions disclose the APR when they advertise a rate. The APR is designed to present the actual cost of obtaining financing, by requiring that some, but not all, closing fees are included in the APR calculation. In addition to the interest rate, these fees determine the estimated cost of financing over the full term of the loan. Since most people do not keep the mortgage for the entire loan term, it may be misleading to spread the effect of some of these up- front costs over the entire loan term. Also unfortunately, the APR doesn't include all the closing fees and lenders are allowed to interpret which fees they include. Fees for things like appraisals, title work, and document preparation are not included even though you'll probably have to pay them. For adjustable rate mortgages (ARMs), the APR can be even more confusing. Since no one knows exactly what market conditions will be in the future, assumptions must be made regarding future rate adjustments. You can use the APR as a guideline to shop for loans, but you should not depend solely on the APR in choosing the loan program that's best for you. Look at total fees, possible rate adjustments in the future if you're comparing ARMs, and consider the length of time that you plan on having the mortgage. Don't forget that the APR is an effective interest rate – not the actual interest rate. In addition, your rate and APR will be based on your creditworthiness and could be higher than the rate shown. Your APR and monthly payments will be based on the actual interest rate, the amount you borrow, and the term of your loan.