Hybrid ARMs are a combination of fixed and ARM loans, starting with a fixed rate for 3,5,7,or 10 years, then rolling into an ARM after the fixed period. These loans are often referred to as a 5/1, or a 3/1, i.e. fixed for 5 years, then adjustable every year, or fixed for 3 years, the 1-yr ARM. The advantage of these loans is that the interest rate is lower than for a 30-year fixed (the lender is not locked in for as long so their risk is lower and they can charge less) but you still get the advantage of a fixed rate for a period of time. If you plan to move to a larger house in 5-7 years, you should look at a 5 or 7 year fixed term, etc.