The interest rate is fixed for the life of the loan, regardless of what rates do over the life of your loan. This ensures that your payment remains the same each month, which can make budgeting a lot easier. However, if your loan has an escrow account that is collecting for taxes or insurance, that likely will change over time and cause your payment amount to change annually. Conventional Fixed Rate Mortgage Loans are typically available in terms of 15, 20 and 30 years.
The interest rate changes periodically by adding what’s referred to as a “margin” to an index specified in mortgage documents. These two numbers are combined to create the loan’s interest rate and often have limits (sometimes referred to as “caps and collars”) that ensure the rate does not increase over a certain amount over the life of the loan. As an example, a 1-year ARM will adjust every year, typically on the anniversary date of the loan. Because the rate changes as the index changes with fluctuations in the market, monthly payments on an adjustable rate mortgage loan likely will be different every year. However, if you are planning on being in your home a short period of time, an ARM may be a very good option with a lower interest rate.