A 7/1 adjustable rate mortgage holds its interest rate fixed for seven years and then resets it on a schedule for the rest of the term. On October 3, 2026, the 7/1 averaged 6.44% against 7.49% for a 30-year fixed, according to Bankrate's daily ARM tracker.

That gap of about one percentage point is why the product comes up on nearly every rate sheet a buyer sees this autumn. The lower rate is paid for with risk after year seven, and the size of that risk is set by three things written into the note: an index, a margin and a set of caps. A borrower who understands those three can judge whether the discount is worth taking.

How the rate is rebuilt after year seven

The 7 is the number of years the rate stays fixed. The 1 is how often it adjusts afterward, once a year, Bankrate notes. For the first 84 payments the loan behaves like a fixed-rate mortgage.

At the first adjustment the lender discards the starting rate and builds a new one from two parts. The first is the index. For loans sold to Fannie Mae and Freddie Mac it is the 30-day average Secured Overnight Financing Rate (SOFR), published by the Federal Reserve Bank of New York. That average stood at 3.705% on September 25, 2026, according to HSH.com.

The second part is the margin, a fixed markup the lender sets at closing that never changes. The standard conforming margin is 2.75%, according to the Fannie Mae Selling Guide and related GSE documentation, and agency loans allow up to 3%. Index plus margin, rounded to the nearest eighth of a point, is the fully indexed rate.

Caps limit how far that new rate can move. Conforming seven-year SOFR ARMs use a 5/1/5 structure, according to the same GSE documentation. The first adjustment can move the rate by up to 5 percentage points. Each later adjustment can move it by up to 1 point. Over the life of the loan the rate cannot exceed the starting rate by more than 5 points.

A hypothetical $400,000 loan at this week's rates

Say a buyer borrows $400,000 on a 30-year 7/1 ARM at 6.44%, Bankrate's October 3 average, with the standard 2.75% margin and 5/1/5 caps. The figures below are calculated from those inputs and rounded.

Monthly principal and interest, years 1 to 7, at 6.44%about $2,513
Same loan as a 30-year fixed at 7.49%about $2,794
Balance owed after 84 paymentsabout $361,300
Reset if SOFR stays at 3.705%: 3.705% + 2.75%, rounded to 6.5%about $2,526
Worst case at first reset: 6.44% + 5 points = 11.44%about $3,715

The ARM saves roughly $281 a month during the fixed period, or about $23,600 over seven years. If the index were unchanged at reset, the payment would barely move. If the rate hit its 11.44% ceiling, the payment would rise by about $1,200 a month, and the lifetime cap means it could go no higher.

Where it shows up

The averages disagree on how large the discount is. Bankrate put the 7/1 at 6.44% against 7.49% for the 30-year fixed on October 3. On the same day NerdWallet reported a 7-year ARM at 7.10% APR against 7.44% APR for the fixed, a gap of about 0.34 point. Part of the difference is that one compares note rates and the other compares APRs, which include fees. Bankrate's own 7/1 APR was 6.85%.

The 7/1 can also price below a shorter ARM. On September 9, 2026, the 5/1 ARM purchase rate jumped 39 basis points to 7.03%, above the 30-year fixed at 6.73%, while the 7/1 sat at 6.51%, according to Nadlan Capital Group. The source attributed the move to lender-specific volatility rather than a market shift.

The spread moves over time. In mid-May 2026 the seven-year ARM was only 19 basis points below the fixed rate, and it was 37 basis points below in early June, according to ListWithClever.

Not the same as a 7/6 or a 5/1

Product Fixed period Adjusts after that Typical caps
7/1 ARM 7 years Once a year 5/1/5
7/6 SOFR ARM 7 years Every 6 months 5/1/5
5/6 SOFR ARM 5 years Every 6 months 2/1/5

Many lenders still advertise a "7/1" when the conforming loan on offer is a 7/6, which ListWithClever describes as the current standard. A 7/6 resets twice as often once the fixed period ends, so the 1-point periodic cap can apply twice a year. Shorter ARMs get a tighter 2% first-adjustment cap, a structure covered in the explainer on the 5/1 adjustable rate mortgage.

Who it fits, and what to check

The 7/1 suits a borrower who expects to sell, refinance or pay off the loan within seven years. That borrower collects the discount and never meets the reset.

The case against is a plan that slips. A refinance in year seven depends on rates then, and a borrower who stays must absorb whatever SOFR has done. The index fell from 4.31% to 3.705% over the past year, according to HSH.com, but nothing in the sources says where it will be in 2033. The worst-case payment above is the figure to test the household budget against, and the effect of Fed policy on ARM borrowers is covered in this week's Fed explainer.

Before choosing, a borrower should confirm four items on each loan estimate: whether the product is a 7/1 or a 7/6, the margin, the cap structure, and the APR alongside the note rate. Quotes on both the seven-year ARM and the 30-year fixed should come from more than one lender. The published averages differ by roughly 0.7 point on the size of the discount, so only a borrower's own quotes show whether the gap justifies the risk.