What Is an Adjustable-Rate Mortgage… and Is It Really That Scary?

Adjustable-rate mortgages (ARMs), also known as adjustable-rate home loans, are a mortgage product that typically start with a fixed interest rate below the current market rate for an initial period and then, after that fixed period, become adjustable at a set frequency (for example, annually or semi-annually). 

If you’re comparing mortgage options, understanding fixed vs adjustable-rate mortgages is key, especially for first-time homebuyers looking for lower monthly payments. 

A Real-World Example 

For this hypothetical scenario, we used a purchase price of $500,000 with a 20% down payment and a loan amount of $280,000 on a single-family home with an A+ credit score. 

30-year fixed-rate mortgage: 
Interest rate: 6.625% 
Approximate monthly payment: $2,562 (principal & interest) 

5/6 Adjustable-Rate Mortgage (ARM): 
Interest rate: 5.25% 
Approximate monthly payment: $2,209 (principal & interest) 

That’s a $353 lower monthly payment, resulting in about $21,180 in savings over the first five years. 

For buyers searching for low monthly mortgage payments or affordable home financing options, this difference can be significant. 

Why Are ARM Rates Lower? 

Lenders offer lower introductory rates on ARMs because the borrower takes on some future interest rate risk. 

What Happens When the Rate Adjusts? 

If you’re wondering about adjustable-rate mortgage risks, here’s what to know: 

If rates go up: 

ARMs come with interest rate caps, including:  

• First Adjustment caps (maximum at first adjustment after fixed period) 
• Subsequent caps (limits per adjustment) 
• Lifetime caps (maximum rate over the loan) 

If rates go down: 

• Your interest rate can decrease as well 
• A floor rate may apply, meaning the rate won’t drop below a certain level 

Always review ARM loan terms, rate caps, and adjustment schedules with your Loan Officer. 

Do People Keep ARMs Long-Term? 

Most borrowers don’t keep their mortgage for 30 years. Many: 

• Refinance when interest rates drop 
• Sell their home 
• Use equity for renovations 

If you plan to move or refinance within 5–7 years, an adjustable-rate mortgage can be a smart strategy to save money upfront. 

Pro Tip 

When comparing ARM vs fixed rate mortgage options, always ask about: 

• Prepayment penalties 
• Adjustment caps 
• Rate floors

(For example, some lenders—including Service Credit Union—do not charge early payoff penalties.) 

A Personal Note 

I purchased my first home at age 22 using an ARM. It can be a powerful mortgage strategy when used correctly.