Contents
- – 7/1 adjustable rate mortgage (7/1 arm) Adjustable Rate Mortgage. the rate is fixed for a period of 7 years after which in the 8th year the loan becomes an adjustable rate mortgage (ARM). The adjustable rate is tied to the 1-year treasury index and is added to a pre-determined margin (usually between 2.25-3.0%) to arrive at your new monthly rate.