ARMs work and discuss some of the issues that you might face as a borrower. It includes ways to reduce the risks associated with ARMs; pointers about advertising and other sources of information, such as lenders and other trusted advisers; a glossary of important ARM terms; and a worksheet that can help you ask the right questions and figure out whether an ARM is right for you. (Ask lenders to help you fill out the worksheet so you can get the information you need to compare mortgages. An adjustable-rate mortgage (ARM) is a loan with an interest rate that changes. ARMs may start with lower monthly payments than fixed-rate mortgages.