How Fixed-Rate Mortgages Work

A fixed-rate mortgage locks your interest rate for the entire loan term, so your principal-and-interest payment never changes. This offers complete predictability — you know exactly what you’ll pay for the life of the loan, regardless of what happens with market rates. That stability is why fixed-rate loans are the most common choice.

How Adjustable-Rate Mortgages Work

An adjustable-rate mortgage (ARM) has an interest rate fixed for an initial period — often several years — then adjusting periodically based on market conditions. ARMs often start with a lower rate than fixed loans, but after the initial period, the rate and payment can rise (or fall) at set intervals, introducing uncertainty.

The Core Tradeoff

The decision comes down to stability versus flexibility. Fixed-rate loans offer certainty and protection against rising rates, at a rate that may start higher. ARMs offer a lower initial rate and payment, with the risk that rates rise later. Your choice depends on how much you value predictability and how long you expect to keep the loan.

Which Suits You?

A fixed-rate loan generally suits buyers who want certainty and plan to stay in the home long-term. An ARM can suit those who expect to move or refinance before the fixed period ends, or who want the lower initial payment and understand the risk. Your timeline, risk tolerance, and the rate environment all factor in — a lender can model both for you.

Frequently Asked Questions

Fixed versus adjustable is really stability versus a lower start with risk — and the right call depends on how long you’ll keep the loan and how much certainty you want.