stack_of_cashMortgage interest rates were still at historically low levels near the end of 2014. The Freddie Mac Primary Mortgage Market Survey said that the average rate on a 30-year fixed-rate mortgage loan ended up in the low 4% range last year. And the average rate on a 15-year fixed-rate loan finished at an even more attractive low 3% range by New Year’s.

But how long will rates remain low? If you haven’t refinanced your mortgage loan yet should you? How high could interest rates climb in 2015?

The unsatisfying answer? No one really knows. The truth is, no one can predict with any certainty where interest rates will head in 2015. But there is a consensus among economists: Rates have been incredibly low for a long time. They’ve been so low, in fact, that there is nowhere for them to go but up. And this means that homeowners who’ve been dawdling on refinancing their mortgage loans need to act quickly before rates start to trend upward.

Freddie Mac predicts that the average rate for a 30-year fixed-rate mortgage may hit 5% by the end of 2015. The Mortgage Bankers Association is predicting the same thing.

And those are the conservative estimates. Lawrence Yun, the chief economist for the National Association of REALTORS®, has said NAR expects the average interest rate on a 30-year fixed-rate mortgage to come in as high as 5.5% by the end of 2015. And if that isn’t shocking enough, Bill Conerly, an economist who frequently writes for Forbes, says he wouldn’t be surprised if the 30-year-fixed average rate rose to 6% by the end of 2015.

Our advice? Don’t put off refinancing any longer.

Here’s why. If you owe $180,000 on your 30-year fixed-rate loan and your interest rate is 4%, your monthly mortgage payment—not counting insurance and taxes—will be about $859. If your rate on that same loan was 6%, your monthly payment—again not counting taxes and insurance—would rise to about $1,079. That’s a difference of about $220 a month, or $2,640 a year.

The good news? There is still time to refinance. You can make the process move smoothly by gathering your necessary paperwork today. To close a refinance, we’ll need copies of such documents as your last two paycheck stubs, last two years’ worth of income-tax return statements and last two months of bank-account statements.

There’s more good news. Housing prices have steadily been rising in most markets across the country. This means that a growing number of homeowners have more equity in their residences. The more equity you have in your home—20% or more is ideal—the easier it is for us to close your refinance. And even if you don’t have much, or any, equity, we might still be able to refinance your loan. Government programs can help.

So don’t delay. The days of low 4% interest rates on 30-year mortgage loans might be numbered. The longer you wait to refinance, the lower your odds of qualifying for one of these historically low interest rates.

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