Fixed vs. Adjustable-Rate Guide Payment shock
How adjustable-rate mortgages really move
Preparing for an ARM increase In brief
Before a reset, check your loan's index, margin and caps to estimate the highest possible new payment. Servicers must send advance notice of the change. Build savings for the higher payment or compare refinance options in time.
Key takeaways Know your index, margin and caps. Watch for the advance notice. Plan for the worst case. Last reviewed October 31, 2026 against the primary sources listed below.
Find Index and margin. Adjustment caps. Next reset date. ARM questions How do I prepare for an ARM reset? Estimate the worst case and plan ahead.
Will I be told before my ARM adjusts? Yes, servicers must send advance notice.
Related reading Simulator Enter your loan amount, initial rate, fixed period, margin, caps and an index scenario to see the rate and payment at the first resets and the worst case. Questions to ask a lender about an adjustable rate Questions that pin down how an ARM can change. ARM anatomy: initial period, adjustments and names like 5/6 How adjustable-rate mortgage names describe the initial fixed period and adjustment frequency, and what happens at each reset. ARM margins and caps explained, including 2/1/5 How the ARM margin works, what initial, periodic and lifetime caps mean, and how to read a cap structure such as 2/1/5. Next: worst-case planning