Are you leaving money on the table when it comes to your mortgage and needlessly overpaying for your house? That’s what many Americans are doing, according to CreditSesame.com, which has found that scores of U.S. homeowners are overpaying their mortgages by about $52,000 over a 10-year period.

An analysis of household data by Credit Sesame found that about eight million American households will pursue a mortgage refinance in 2011. But according to data from Credit Sesame, more than 20 million U.S. households actually qualify for a refinance and would benefit from it significantly.

So why the disparity, or why are roughly residents of 12 million U.S. households missing out on refinancing their home loans and saving money such a large pot of money?

CreditSesame.com CEO Adrian Nazari believes it boils down to three things.

First, despite all the media reporting about interest rates being at historically low levels, some people simply remain unaware of the big potential for savings. So certain homeowners may hear about low rates, but not have a concrete idea about how much money they could pocket each month if they successfully refinanced.

Second, some consumers are just flat-out disenchanted. Sure, they’re heard about low interest rates. But they’re heard a lot more about the ongoing credit crunch. These potential borrowers are keenly aware that lenders have tightened their credit standards. So this group of homeowners is so worried or doubtful about their own ability to qualify, that they’ve effectively thrown in the towel before they really even get started with a refi application.

Then there’s a third group of consumers who are outright discouraged. Maybe they went to one bank or perhaps even two, and they got turned down for a home loan. Maybe their credit was marginal. Maybe the home equity in their home was deemed by one lender to be insufficient. Maybe they didn’t show enough income according to another lender.

Whatever the case, they might actually qualify for a loan, if only they were willing to shop around and further explore their options. But so far, these consumers haven’t taken the time to fully investigate their options.

How Much Can You Save?

Now, the interesting thing about the statistics from Credit Sesame is that the company looked at people who, realistically, would qualify for a home refinance.

So we’re not talking here about the roughly 25% of homeowners nationwide who are underwater and they owe more on their homes than those properties are worth. Clearly lenders are not going to lend against those houses.

Instead, Credit Sesame analyzed data from its user base of people who actually would qualify. These are individuals who could reap tremendous savings and get a mortgage approval based on a number of factors, such as their credit standing, the equity in their home, and so forth.

Credit Sesame says that, on average, Americans who do qualify for a refi but have not yet pursued refinancing, are overpaying about $436 per month on their mortgage. That works out to be about $52,000 over a 10-year period.

So my advice is this: don’t let one rejection from a lender turn you away and prevent you from doing a refinance if it would be a smart decision for you to do so.

Most of us could use a little extra cash. And I know plenty of people who would literally jump at the chance in order to get a reduction of their mortgage – especially if they knew the true cost savings to be reaped, and that it wasn’t going to be too much of a hassle to get the refi process done.

Again, the savings that you can rack up with a refi is significant, and that’s true even in places like Nevada where there are so many homes underwater. The average savings for those who are foregoing the opportunity to refi in Nevada is roughly $38,000 over a 10‑year period.

In New Jersey, where I live, the average savings is $97,000 for those who could reasonably qualify for a refinance.

So if you’re a homeowner and could stand to put a big chunk of money back in your wallet, this is definitely something worth considering. And if you have a chance to refinance, I would encourage you to explore it right away.