With a fixed-rate mortgage, the interest rate stays the same during the life of the loan. With an adjustable-rate mortgage (ARM), the interest changes periodically, typically in relation to an index. While the monthly payments that you make with a fixed-rate mortgage are relatively stable, payments on an ARM loan will likely change. There are advantages and disadvantages to each type of mortgage, and the best way to select a loan product is by talking to one of our loan originators.