If you are more comfortable in taking a risk with your money or if interest rates are very high at the time you take out your loan, an adjustable-rate mortgage (ARM) may be the solution for you. You might also choose this type of loan if your planned ownership of the property is short-term or if you expect your income to increase to cover any potential rise in the interest rate.

Generally, the interest rate when you take out your loan will be lower than a fixed-rate mortgage. Please note that this is true initially, not necessarily long-term.

Since an ARM rate rises and falls depending on the prevailing interest rate, your mortgage payment will rise and fall accordingly. If your income is not sufficient to cover the highest possible payments, then this option is not for you. On the positive side, the lower initial payments will allow you to qualify for a larger loan than if you choose a fixed-rate. The downside is that your payments will increase if/when the rates go up.

Typically, ARM interest rates are tied to a specific financial index (such as Certificate of Deposit index, Treasury or T-Bill rate, Cost of Funds-Indexed Arms or COFi, or LIBOR [London Interbank Offered Rate]) and your payment will be based on the index your lender uses plus a margin, generally of two to three points. Get the formula used by your lender in writing and make sure you understand what it means.

Fortunately, the amount an ARM can increase is limited. There are "caps" on how much your lender can increase your rate, both for a period of one year and for the life of the loan. Plan ahead, and have your lender calculate what the maximum payment would be if your rate went to the highest amount allowed by the cap for your particular mortgage. If you are not confident you'll be able to pay that amount on a monthly basis, perhaps you should reconsider this type of loan.