All these benefits do cost something, though. When you refinance, you're paying for most of the same things you paid for when you obtained your original mortgage. These might include settlement costs and other fees, an appraisal, lender's title insurance, underwriting fees, and so on.

You might have to pay a penalty if you refinance your previous mortgage too quickly. That depends on the terms of your existing mortgage. These penalties are illegal in some places, and more often than not when they're there apply only for the first year or two. We'll help you figure it out.

You might pay points to get a more favorable interest rate. If you pay three percent of the loan amount up front, your savings for the life of the new mortgage can be significant. You should be aware that the IRS has recently said that points paid for the purpose of refinancing your mortgage cannot be deducted in their entirety in the year you pay them, unless the refinanced loan is primarily for home improvements. Consult your tax professional before deducting points you pay on your new mortgage from your federal income taxes.

Speaking of taxes, if you lower your interest rate, naturally you will be lowering the amount of mortgage interest payments you can deduct from your federal income taxes. This is another cost that some borrowers consider.