A hybrid adjustable-rate mortgage (ARM) is one where the interest rate on the note is fixed for a period of time, then floats thereafter. The "hybrid" refers to the blend of fixed rate and adjustable rate characteristics found in hybrid ARMs. Hybrid ARMs are referred to by their initial fixed period and adjustment periods, for example 3/1 for an ARM with a 3-year fixed period and subsequent 1-year rate adjustment periods. The date that a hybrid ARM shifts from a fixed-rate payment schedule to an adjusting payment schedule is known as the reset date. After the reset date, a hybrid ARM floats at a margin over a specified index just like any ordinary ARM.