ARM vs Fixed: Which Is Right for You?
The choice between an adjustable-rate mortgage and a fixed-rate mortgage depends on your time horizon, risk tolerance, and market outlook. ARMs offer lower initial rates but carry the risk of future rate increases. Fixed-rate mortgages provide payment certainty for the entire loan term.
How ARMs Work
A 5/1 ARM has a fixed rate for the first 5 years, then adjusts annually based on a market index plus a margin. Rate adjustments are limited by periodic caps (how much it can change per adjustment) and a lifetime cap (the maximum rate over the life of the loan, typically 5% above the initial rate).
Frequently Asked Questions
When does an ARM make sense?â–¾
An ARM makes the most sense when you plan to sell or refinance before the initial fixed period ends, when you expect rates to fall in the future, or when the rate difference between ARM and fixed is substantial (1%+). If you are confident you will move within 5-7 years, the ARM savings can be significant.
What is a rate cap structure (2/2/5)?â–¾
ARM caps are expressed as three numbers: initial adjustment cap / periodic adjustment cap / lifetime cap. A 2/2/5 cap structure means the rate can increase up to 2% at the first adjustment, up to 2% at each subsequent adjustment, and up to 5% total over the initial rate during the loan's lifetime.
Can I refinance out of an ARM?â–¾
Yes, many ARM borrowers plan to refinance into a fixed-rate mortgage before the adjustment period begins. However, refinancing depends on future interest rates, your home's value, and your creditworthiness at that time. Do not assume you will be able to refinance at a favorable rate.
Can ARM rates decrease?â–¾
Yes, ARM rates can go down as well as up, depending on the index they are tied to (such as SOFR or the 1-Year Treasury). If market rates decline, your ARM payment could decrease at the next adjustment. This is the upside scenario that makes ARMs attractive in high-rate environments.
Calclypso Editorial Team
Reviewed by certified financial professionals. Last updated: April 2026. ARM worst-case projections assume maximum rate adjustments at each period.