A loan with a set interest rate throughout the life of the loan regardless of whether rates go up or down. The most common mortgage is known as a 30-year fixed which means that the loan is paid over a 30-year period, and the interest rate is fixed at the time of the purchase. Most FHA loans and VA loans are fixed-rate mortgages. The other main type of mortgage is an adjustable-rate mortgage (ARM), which has a variable interest rate.