adjustment interval

The period between the alterations in an adjustable rate mortgage's monthly payment or interest rate. The adjustment interval is typically shown as the ratio of X/Y, where "X" is the amount of time until the initial modification on the rate, and "Y" is the period of adjustment after the first modification is made. For instance, a 7/1 ARM occurs when the initial rate is the same for seven years, but is adjusted every year after that. On a fully amortizing ARM, the adjustment intervals for both rate and payment are the same; this may not be the case with a negative amortization ARM.