When you're offered a "rate lock" from a lender, it means that you are guaranteed to keep a set interest rate over a determined period for the application process. This keeps you from getting through your whole application process and discovering at the end that the interest rate has gone up.
Rate lock periods can vary in length, between fifteen to sixty days, with the longer spans typically costing more. You can get a longer period for your lock, but in making this choice, will probably have a higher rate than you would with a shorter rate lock period
In addition to choosing a shorter rate lock period, there are other ways you may be able to attain the lowest rate. A bigger down payment will result in a better interest rate, since you'll have more equity from the beginning. You can pay points to reduce your rate over the loan term, meaning you pay more initially. To a lot of people, this is a good option..
Do you have a question regarding a mortgage program?