While tax reform isn't exactly a sure thing just yet, it does appear that the standard deduction could rise and the popular mortgage interest deduction could become far less useful to many people. The good news is that if you plan to claim the mortgage interest deduction on your 2017 tax return, there's a way to squeeze some extra tax savings out of it.

One important point to know about the mortgage interest deduction

Under current tax law, mortgage interest on up to $1 million in mortgages is tax-deductible for taxpayers who choose to itemize deductions. This can be a mortgage used to construct, buy, or improve a first or second home. In addition, interest on up to $100,000 of home equity debt can be deductible. For individuals who use the "married filing separately" tax filing status, these debt limits are cut in half.

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Here's the key point for the purposes of our discussion. The deduction is based on the mortgage interest you actually paid during the calendar year, which will be reported by your mortgage servicing company on Form 1098. It is not based on the amount of interest that was due during the calendar year.

This means that you can make your 12 regularly scheduled mortgage payments that are due throughout 2017 and can make your January 2018 payment before 2017 comes to an end. By doing this, you'll have paid 13 months' worth of mortgage interest during 2017 and could be entitled to a larger mortgage interest deduction.

Why it could be smart to take advantage in 2017

There are two big reasons to make your January mortgage payment before the end of 2018, and they both have to do with tax reform.

First, virtually everyone involved in the tax reform process is advocating a standard deduction that is roughly twice the current amount. In order to take advantage of the mortgage interest deduction, you need to itemize deductions on your tax return. Well, the combination of a significantly higher standard deduction and the elimination of many other potential deductions would mean that far fewer people would be able to use the deduction at all, even if they've been using it for years.

Second, even if you are able to take advantage of the mortgage interest deduction in 2018, there's a strong possibility that your marginal tax rate will be lower next year. For example, if you're in the 28% tax bracket now and find yourself in the 25% tax bracket next year, every dollar in deductions becomes slightly less valuable to you. To be clear, a lower marginal tax rate is a good problem to have, but my point is that if this is the case, maximizing your deductions in 2017 could be the smarter move.

Finally, it's also worth mentioning that the first version of the tax reform bill would cut the maximum amount of mortgage debt usable for the deduction in half to $500,000; however, this would not apply to existing loans.

How much more could you save?

While it's impossible for me to tell you how much this could affect you without knowing your mortgage balance, interest rate, and marginal tax bracket, this move could easily translate into tax savings in the hundreds. To estimate your savings, check out how much of your mortgage payments go to interest -- you can usually find a breakdown of your monthly payment on your latest mortgage statement, or for a month-by-month breakdown, look for your amortization schedule, either online or in paper form.

Once you know about how much interest your January 2018 payment will represent, multiply this amount by your marginal tax rate, or tax bracket. For example, if you'll pay $600 in additional interest and you are in the 25% tax bracket, making an additional mortgage payment before the end of 2017 could save you $150 on your taxes.

The bottom line that saving money on your taxes is always a plus, and taking full advantage of the mortgage interest deduction in 2017 could be an especially smart move since the deduction may not be as advantageous in future tax years.

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