Understanding adjustable rate mortgages

An Adjustable Rate Mortgage, sometimes referred to as an ARM, has a lower rate and lower monthly payments for the first 3, 5 or 7 years, depending on the term you choose. But after an initial period, your rate and payment may change, based on interest rates at the time. The interest rate is not fixed for the entire life of the loan.  The rate is fixed for a specified period, such as; 3, 5 or 7 years known as the “initial rate period”, but after that it may change based on movements in an interest rate index.