For both new buyers and refinancers, it's important to understand what a no-cost mortgage loan or a no-cost refinance loan really means. "No cost" does not mean that closing costs (also known as settlement costs) have been erased. It means that the closing costs will be factored into the interest rate associated with the loan. Of course, this also means that, all other things being equal, the interest rate associated with a no-cost mortgage will always be higher than one where the borrower pays the closing costs up front.
These days most people request a Good Faith Estimate (GFE), but have no clue what to look for on the GFE. Make sure you request a GFE that has ALL fees estimated and disclosed. This includes: origination points, processing, lender, appraisal, title, escrow... ALL FEES... especially the Yield Spread Premium or YSP.
You can also save money on your mortgage refinancing by paying "points." This is a fee that effectively lowers the interest rate of your loan. If you plan on staying in your home for a long time, this long-term strategy can be an excellent way to save thousands of dollars.
If there are only a few years left on your current loan, it's no use refinancing with a long term loan. You may need extra cash but with a long term loan, you'll end up paying more for the entire loan term.