I would avoid adjustable rate mortgages all together. If you have a fixed rate it will not change. You can "pay down" the rate upfront though. If you want to pay down your rate however, make sure it's worth the money, For example, if it costs you $2,000 to buy down the rate .250% and save you $35 a month, it will take you almost 5 years to make that money back. So make sure if you buy down your rate, it makes sense.