ARM Mortgage Rates

What are ARM mortgage rates? 

The initial mortgage interest rate on an ARM is often lower than comparable fixed-rate mortgages, which can make ARMs attractive to borrowers who want lower monthly payments in the early years of their loan. This lower starting rate can help buyers qualify for a larger loan amount or reduce their housing costs during the initial period. However, once the adjustment period begins, the rate—and the monthly payment—can increase or decrease based on changes in an underlying interest rate index.

An Adjustable-Rate mortgage (ARM) is a type of home loan where the interest rate can change over time, unlike a fixed-rate mortgage where the rate stays constant for the entire loan term. ARM rates typically start with an initial fixed-rate period—commonly 3, 5, 7, or 10 years—during which the interest rate remains unchanged. After this introductory period ends, the rate adjusts periodically based on market conditions, usually once per year or every six months, depending on the loan terms.

ARMs come with certain protections called "caps" that limit how much the interest rate can change. There are typically three types of caps: an initial adjustment cap (limiting the first rate change after the fixed period), a subsequent adjustment cap (limiting changes at each adjustment period), and a lifetime cap (limiting the total rate increase over the life of the loan). For example, a 5/1 ARM with a 2/2/5 cap structure means the rate is fixed for 5 years, adjusts annually thereafter, can change by no more than 2% at the first adjustment, no more than 2% at each subsequent adjustment, and no more than 5% total over the life of the loan.

These mortgages work best for borrowers who plan to sell or refinance before the adjustment period begins, expect their income to increase significantly, or anticipate that interest rates will remain stable or decline. However, they carry more risk than fixed-rate mortgages because future payments are uncertain, and if rates rise substantially, monthly payments could become unaffordable.

ARM vs fixed-rate mortgage

A fixed-rate mortgage keeps the same interest rate for the entire loan, while an ARM starts with a lower rate that can change after an initial period (usually 3, 5, 7, or 10 years).

ARMs typically offer rates that are 0.5% to 1% lower initially, which can save you hundreds of dollars per month at first. However, once the fixed period ends, your ARM rate adjusts based on market conditions and could increase significantly, raising your monthly payment.

Fixed-rate mortgages cost more upfront but protect you from future rate increases, giving you predictable payments for the life of the loan. ARMs work best if you plan to sell or refinance before the rate adjusts, while fixed-rate mortgages are better for long-term homeowners who want payment stability.

The right choice depends on how long you'll keep the home and whether you're comfortable with payment uncertainty.