Most of us−maybe all of us−want to be sure that we've gotten the lowest possible interest rate when we apply for a home mortgage, whether a purchase money loan or a refinancing loan. No news here.

The news, though, is that it is far more difficult to be sure you have the loan that will cost you the least than most people realize. With an adjustable rate mortgage, it's impossible to predict where the monthly payment will go over the life of the loan. With a fixed-rate mortgage, you know that the monthly principal and interest payment will remain the same over the life of the loan, but do you know that you are paying less for Loan A than you would have for Loan B?

Truth is, you may not. And the federally-mandated Annual Percentage Rate (APR) is rarely much help, because even two different computer programs−not to mention people−will come up with different APRs for the same loan because they ignore different fees.

What to do? Check the Good Faith estimates and, better, copies of closing statements for the loans you wish to compare. Add up all the costs. Do the math yourself. Equally important, find the best and most compatible mortgage and real estate advisors that you can. For assistance with all your real estate needs call Beth at (425) 450-5208 and visit her website at www.bethbillington.com.

Beth Billington is a Realtor® with Coldwell Banker Bain in Bellevue, WA.