Adjustable-rate mortgages (ARMs) are finding their way back into more homebuying conversations. ARMs accounted for 10.3% of mortgage applications in the week ending October 2, holding at their highest share since October 2025, according to the Mortgage Bankers Association's October 7 report. Meanwhile, the average contract rate on a conforming 30-year fixed mortgage climbed to 7.49%, its highest level in nearly three years.
That rate gap is hard for cash-strapped buyers to ignore. But an ARM's appeal rests on more than what the payment looks like today. Agents don't underwrite loans, and they shouldn't try. They can, however, make sure clients know what to ask before a lower introductory payment becomes the basis for an offer.
Why buyers are considering ARMs
The numbers explain the renewed interest. The average 5/1 ARM rate slipped to 6.43% in the latest survey, more than a percentage point below the 30-year fixed rate.
On a $400,000 loan with a 30-year repayment term, that works out to roughly $2,795 in monthly principal and interest on the fixed mortgage, versus $2,510 initially on the ARM. The difference is approximately $285 a month, before taxes, insurance and upfront loan costs.
There's a catch in the upfront pricing, though. ARMs in the survey averaged 1.69 points, compared with 0.84 for fixed mortgages, including origination fees. A smaller monthly payment doesn't necessarily mean a cheaper loan, particularly if the buyer pays more to get that rate.
How ARM rate adjustments work
The introductory period is only the first chapter of an ARM. A 5/1 loan generally holds its starting rate for five years before annual adjustments begin. A 7/6 ARM keeps that rate for seven years, then can adjust every six months.
What happens afterward depends on the loan's formula. The new rate generally follows a market index plus the lender's margin. As the Consumer Financial Protection Bureau explains, the index moves with market conditions, while the margin generally stays fixed.
Then come the caps. A 2/1/5 structure, for example, generally limits the first rate change to two percentage points, subsequent changes to one point each and the lifetime increase to five points above the starting rate. Those limits offer some protection, but they don't promise an affordable payment after the introductory period.
5 ARM loan questions every buyer should get in writing
Before an ARM's lower starting payment shapes an offer, buyers should get five answers from their lender:
- What do the fixed-rate and ARM options actually cost? Ask for interest rates, annual percentage rates (APRs), points, closing costs and monthly payments side by side. Agents can help clients compare mortgage lenders, but the final comparison should use the buyer's actual loan terms.
- What index and margin apply, and when does the rate change? The introductory period has an expiration date. Buyers should know when adjustments begin, how often they occur and what determines the new rate.
- How high could the monthly payment climb? Have the lender calculate the first possible adjustment and the maximum permitted payment. Different ARM rate caps can produce very different outcomes, even when two loans start at the same rate.
- How do the costs compare over the buyer's expected ownership period? Run the numbers against the planned time in the home, including fees and possible adjustments. Selling or refinancing before the rate changes may sound reasonable, but plans have a way of changing.
- Could the buyer afford the adjusted payment? Ask about a longer introductory period, a fixed-rate alternative or a different down payment. Rate floors and potential prepayment penalties also deserve a place in the conversation.
What an ARM payment estimate leaves out
A principal-and-interest quote isn't the whole housing bill. Property taxes, homeowners insurance, mortgage insurance and HOA dues can change what a buyer can comfortably carry.
That's why the lender's Loan Estimate deserves a close look. Lenders generally must provide one within three business days of receiving an application containing the required information. Comparing estimates before financing deadlines expire gives buyers a firmer basis for choosing between loans.
What ARM risk still looks like
An ARM can make sense for someone who expects to move within a few years. But future rates aren't guaranteed, and neither is an easy refinance. As recent mortgage rate increases have illustrated, borrowing costs can shift faster than a buyer's plans.
Agents can't control where rates go next. What they can do is send clients back to their lenders for updated numbers before an offer goes out. A mortgage should work for the buyer's budget beyond the first few years, not just on the day they sign.