Adjustable Rate Mortgages - The Basics

Adjustable Rate Mortgage (ARM) Components:

1. Index: The interest rate of an ARM is tied to an economic index, such as the 1-year constant maturity Treasury security, the Cost of Funds Index, or the London Interbank Offered Rate (LIBOR). The movement of the index determines the adjustment of the ARM's interest rate.
2. Margin: The margin is a fixed percentage added to the index to calculate the ARM's interest rate. It represents the lender's profit margin on the loan and remains constant throughout the loan term.
3. Adjustment Period: This refers to the frequency with which the ARM's interest rate adjusts. For example, if the adjustment period is one year, the interest rate will change annually, leading to recalculated monthly mortgage payments.
4. Interest Rate Cap: Interest rate caps are limits placed on how much the interest rate or monthly payment can change during each adjustment period or over the life of the loan. Caps protect borrowers from significant fluctuations in interest rates and payments.
5. Initial Interest Rate: The initial interest rate is the rate at which the ARM begins, typically lower than the rate for a fixed-rate mortgage. This rate remains fixed for an initial period, which can range from one to several years, depending on the specific loan terms. After the initial period, the interest rate adjusts according to the index and margin.
6. Hybrid ARM: Some ARMs offer an initial fixed-rate period followed by adjustable rates for the remainder of the loan term. For example, a 5/1 ARM has a fixed rate for the first five years and then adjusts annually thereafter.

In summary, an ARM's components include an index, margin, adjustment period, interest rate cap, and initial interest rate. Borrowers should carefully consider these factors when choosing an ARM, as they determine the variability and potential risks associated with the loan's interest rate and payments.