Definition

An ARM or adjustable rate mortgage is a type of mortgage loan where the home loan rate fluctuates periodically depending on any of an index measurements. Common indexes used include Prime rate plus x, LIBOR (London Interbank offered rate) or other index, including one developed by the lender. This causes the payment amount to vary or the term of the loan to vary to cover the increased (or sometimes decreased) amounts owed. Adjustable rate mortgages have the effect of transferring part of the risk of making the loan from the lender to the borrower. The rates of ARMs usually start lower, but can increase at a much faster rate than the borrower is prepared to cover.

Advantages

In times of expanding earnings and economy, adjustable rate mortgages are a good deal for the borrower, because it allows them to get a larger loan than they would have been able to afford otherwise. The home loan rate starts out at a lower level and then increases (usually) after a waiting period to keep pace with increasing interest rates. The ease of obtaining an adjustable rate mortgage and the lower payments in the beginning are two major advantages of this type of loan. If the borrower's income increases over time, the ARM is the ideal way to get started with home ownership.

Disadvantages

The major disadvantage of obtaining a mortgage with a home loan rate that is tied to an outside index is that in most instances, the rates increase over time. If the borrower has obtained a loan with payments at the top end of the borrowing capability, and the interest rates on the loan rise dramatically, the borrower may find that pay raises or earning capacity have not increased as rapidly as the payments on the mortgage loan. It can be very easy to find oneself in a foreclosure mode when this happens.

Prime rate

The prime rate, or the rate at which the best banks can borrow money is one of the favorite indexes used to calculate the home loan rate. For instance, the mortgage loan may be listed as prime rate plus two percent. If the mortgage loan is an adjustable rate mortgage, the loan may be structured to start at prime rate plus two percent. If the prime rate increases by one quarter percent, the loan can be increased over time to cost the extra one quarter percent. Usually, the amount cannot be increased more than so many times in a time period. There is also usually a top limit to growth for the loan payment.

How are they obtained?

Any mortgage lender can agree to lend the borrower money using an adjustable rate mortgage. In fact, lenders approve of such loans since they remove part of the risk of lending money from the lender and place it upon the borrower. When the home loan rate increases to the lender, it can in turn be passed on to the borrower. Personal financial advisors often suggest that adjustable rate mortgage are something to be very sure you understand what you are getting and what can go wrong.