When you are offered a "rate lock" from the lender, it means that you are guaranteed to get a specific interest rate for a determined period while you work on your application process. This saves you from working through your entire application process and finding out at the end that your interest rate has risen higher.
While there are several lengths of rate lock periods (from 15 to 60 days), the longer spans are typically more expensive. You can get a longer period for your lock, but in making this choice, will likely have a higher rate than you would with a shorter span of time
In addition to going with the shorter lock period, there are more ways you can score the lowest rate. The bigger down payment you pay, the smaller the interest rate will be, since you will have more equity from the beginning. You may opt to pay points to lower your rate for the loan term, meaning you pay more initially. For many people, this is a good option..
Do you have a question regarding a mortgage program?