With a fixed rate mortgage, the interest rate and the amount you pay each month remain the same over the entire mortgage term, traditionally 15, 20 or 30 years. A number of variations are available, including five- and seven-year fixed rate loans with balloon payments at the end. With an adjustable rate mortgage (ARM), the interest rate fluctuates according to the indexes. Initial interest rates of ARMs are typically offered at a discounted ("teaser") interest rate lower than fixed rate mortgage. Over time, when initial discounts are filtered out, ARM rates will fluctuate as general interest rates go up and down. Different ARMs are tied to different financial indexes, some of which fluctuate up or down more quickly than others. To avoid constant and drastic changes, ARMs typically regulate (cap) how much and how often the interest rate and/or payments can change in a year and over the life of the loan. A number of variations are available for adjustable rate mortgages, including hybrids that change from a fixed to an adjustable rate after a period of years.