Are Adjustable Rate Mortgages Worth Your Consideration?

Originally published December 2010. Updated March 2026.

Adjustable-rate mortgages — ARMs — tend to get a bad reputation, largely because of their association with the mortgage crisis of the mid-2000s. But lumping all ARMs together misses an important distinction: the problem back then wasn’t adjustable rate mortgages themselves, it was option ARMs and loose lending standards. A well-structured ARM, used in the right situation, can still be a smart financial tool.

How ARMs Work

An ARM has two phases: a fixed period and an adjustable period. A 7/1 ARM, for example, carries a fixed rate for the first seven years, then adjusts once per year after that. A 10/1 ARM is fixed for ten years before adjusting annually.

When the loan enters its adjustable phase, the new rate is calculated by adding a margin to a benchmark index. Today, the most commonly used index for ARMs is the Secured Overnight Financing Rate (SOFR), which replaced the older LIBOR index that was phased out in 2023. Your loan documents will specify both the index and the margin used for your particular loan.

Understanding Caps

One of the most important features of any ARM is its cap structure, typically expressed as three numbers — for example, 5/2/5:

• The first number is the maximum the rate can increase at the first adjustment
• The second number is the maximum it can increase or decrease at any subsequent annual adjustment
• The third number is the lifetime cap — the maximum the rate can ever increase above your starting rate

These caps provide a defined worst-case scenario, which makes it possible to plan ahead even if you aren’t sure what rates will do in the future.

Who Might Benefit From an ARM?

An ARM isn’t right for everyone, but it deserves consideration if:

• You have a clear plan to sell or pay off the mortgage before or near the end of the fixed period
• You want to maximize cash flow during the fixed period and apply the savings toward principal
• You’re purchasing or refinancing and the fixed period aligns well with your anticipated timeline in the home

The key is matching the loan structure to your actual financial plan — not just choosing the lowest initial payment without thinking through what happens at adjustment.

The Bottom Line

A 30-year fixed rate mortgage remains the most straightforward choice for buyers who want predictability and plan to stay long-term. But if your situation calls for flexibility — whether that’s a planned move, a payoff timeline, or managing cash flow during a specific life stage — an ARM structured around your goals is absolutely worth a conversation.

Have questions about whether an ARM might make sense for your situation? I’m happy to walk through the numbers with you.