Also called a variable-rate mortgage, an adjustable-rate mortgage has an interest rate that may change periodically during the life of the loan in accordance with changes in an index such as the U.S. Treasury-Index (T-Bill) or the Secured Overnight Financing Rate (SOFR). Bank of America ARMs generally use SOFR as the basis for ARM interest rate adjustments.
Your monthly payment may fluctuate as the result of any interest rate changes, and a lender may charge a lower interest rate for an initial portion of the loan term. Most ARMs have a rate cap that limits the amount of interest rate change allowed during both the adjustment period (the time between interest rate recalculations) and the life of the loan.