An adjustable rate mortgage (ARM) provides a fixed initial interest rate and a fixed initial monthly payment for a short period of time. With an ARM, after the initial fixed period, which can be anywhere from six months to six years, both the interest rate and the monthly payments adjust on a regular basis to reflect the then current market interest. Some ARMs may be subject to adjustment every three months while others may be adjusted once a year. Also, some ARMs limit the amount that the rates can change. While an ARM usually carries a lower initial interest rate and lower initial monthly payment, the purchaser is taking the risk that rates may rise in the future.