Adjustable Rate Mortgage

Adjustable Rate Mortgages (ARMs) are attractive to many homebuyers for one reason: lower payments in the first years of the loan. Typically, an ARM will have a low introductory rate, sometimes called a "teaser" rate. This rate is usually much lower than the fixed rates available at that time.

Adjustable rate mortgages (ARMs) have payments that usually increase or but can sometimes decrease on a regular schedule, and are linked to specific economic indexes or margins. These indexes measure borrowing and lending costs throughout the United States and are independent of the lender and can be independently verified at any time. (Many ARMs are indexed to Treasury bills or securities, Certificates of Deposit and other rates.)

How and When do ARMs Adjust?
When comparing ARMs that have different indexes, look at how the index has performed recently. Some indexes are published in newspapers, making them easy to track. Lenders are required to provide you with information on how to track the index and a 15-year history of the index, but keep in mind that past performance is not necessarily indicative of future performance.

An ARM will have a low Initial Interest Rate, sometimes called "teaser" rate. The loan will begin to adjust at a certain interval, usually every six months or annually. When the loan adjusts, the lender will use three things to determine the new interest rate: the index, the margin and the cap(s).

Index
The index is a benchmark by which changes in the market interest rates are gauged. Common indexes include the 1 Year T-bill, the 11th District Cost of Funds, Prime, LIBOR, or even Certificate of Deposit (CD) rates.

Margin
In order to determine the new rate on the adjustment date, the index is added to the margin. The easiest way to understand the margin is to put the word "profit" in front of it. It is the amount of excess of the index that the lender is going to charge in interest; it is essentially the lender’s profit margin.

Rate Caps
To insure that your payments do not change dramatically in any given six-month or one-year period, adjustable rate mortgages provide protection in the form of interest rate caps. There are two kinds of interest rate caps: periodic (annual, semi-annual, etc.) and lifetime. For example, a loan may have a semi-annual rate cap of 1%, or an annual rate cap of 2%. The loan will also have a lifetime rate cap, frequently 6% over the initial rate. The caps insure that even if interest rates rise rapidly, the monthly mortgage payment will not be as dramatically affected.