- – 5/1 arm 5/1 Adjustable Rate Mortgage . 5/1 ARM – the rate is fixed for a period of 5 years after which in the 6th year the loan becomes an adjustable rate mortgage (ARM). The adjustable rate is either tied to the 1-year treasury index or to the one-year London Interbank Offered Rate ("LIBOR"), and is added to a pre-determined margin (usually between 2.25-3.0%) to arrive at your new monthly.
Compare Today's 5/1 ARM Mortgage Rates – NerdWallet – A 5/1 adjustable rate mortgage (5/1 ARM) is an adjustable-rate mortgage (ARM) with an interest rate that is initially fixed for five years then adjusts each year. The "5" refers to the number of initial years with a fixed rate, and the "1" refers to how often the rate adjusts after the initial period. The initial fixed interest.