Looking for a Late Tax Deduction?

Now that January is solidly underway, many investors are starting to prepare their tax return paperwork. At the very least, many are reviewing their finances from the past year and trying to figure out what they might expect in terms of a tax refund -- or a tax bill.

The good news is that, if you're reviewing your accounts and you think you might be able to improve your situation, it's still possible to get a tax deduction for the previous year. If you have a traditional individual retirement account (IRA) or a health savings account (HSA), it's possible for you to make a previous-year contribution.

[Read: How to Use Your Portfolio to Save on Taxes All Year.]

Here are three things to know:

-- Who can make a previous-year contribution.

-- Benefits of a previous-year contribution.

-- How to make a previous-year contribution.

Who Can Make a Previous-Year Contribution?

Some accounts allow you to make a previous-year contribution and claim a tax deduction, even if Jan. 31 has passed, which can be a helpful tax planning tool for investors. Two of the most popular accounts that allow this possibility are a traditional IRA and an HSA.

As long as you haven't maxed out your contributions, you can make additional contributions and claim a tax deduction.

For example, if you have a family, you might be eligible to contribute up to $7,000 to an HSA for 2019. Perhaps you've only contributed $5,000. If you have $2,000 available, you can make an additional contribution -- as long as you do it before Tax Day.

The same goes for a traditional IRA contribution. Maybe you only contributed $3,000 to your traditional IRA in 2019. Because the contribution limit is $6,000 for 2019, you still have room to contribute up to $3,000 more. If you're eligible for a tax deduction on your contributions, this could allow you to put more in your retirement account.

If you have a spouse with a traditional IRA, it's possible for them to make their own previous-year contribution and boost your joint tax deduction.

Benefits of a Previous-Year Contribution

The most obvious benefit of a previous-year contribution is the fact that you can impact your tax bill.

Maybe you're close to being bumped into the next tax bracket, but a deduction can reduce your income enough to keep you out of that bracket. Even if you're not about to move into another tax bracket, a previous-year contribution can still reduce your taxable income, and your tax bill.

If you're expecting a refund, you might see a bigger refund by making this move. A deduction that reduces your taxable income and allows you to see increased benefit from a refundable tax credit can make a difference in your finances going forward.

And, of course, as an investor, there are benefits when you can set more money aside in a tax-advantaged account. This is especially true of an HSA.

[See: 6 Ways to Invest Your Emergency Fund.]

With an HSA, the money you contribute comes with a tax deduction, but it also grows tax-free if used later for qualified health care expenses. You can invest money in your HSA and reap benefits of tax-free growth for years to come.

By maxing out your HSA each year, you could see huge benefits down the road.

Your previous-year contribution to a traditional IRA also has an advantage. While you'll have to pay taxes on distributions later, you can benefit by taking advantage of tax-deferred investing.

Finally, even though you won't get an immediate tax benefit, it might make sense to make a previous-year contribution if you have a Roth IRA. If you didn't max out your Roth IRA contribution last year, you're missing out on tax-free gains.

Even if you don't see a benefit today, being able to boost your investment portfolio with more capital that will earn returns tax-free, you're still helping your future self.

How to Make a Previous-Year Contribution

Making a previous-year contribution is fairly straightforward.

If you manage your tax-advantaged investment account online, you can usually go in and decide to make a one-time contribution. When you select this option, you should be presented with the ability to identify the contribution as being a previous-year contribution.

Carefully read through everything as you go through this process. You want to be sure that you're making the right election. Double-check that you've selected a previous-year contribution before you finalize the contribution.

If you have to make the contribution with the help of a custodian, be very clear when you talk to them that you want to make a previous-year contribution and ask for confirmation in writing.

It's vital that you have your contribution credited to the appropriate year, or you could end up over-contributing for one year, and that comes with its own set of hassles and headaches.

[See: Stop Believing These 7 Investing Myths.]

As long as you make your previous-year contribution by Tax Day of the current year, you should be good to go and able to reap the benefits of increasing the amount you invest in a tax-advantaged account.

Miranda Marquit has more than a decade of experience covering financial markets, investing, business, and personal finance topics. She has made contributions to a wide variety of media outlets, including Forbes, NPR, FOX Business, Entrepreneur, Yahoo! Finance, USA Today, Investopedia, The Balance, and MSN Money, in addition to U.S. News & World Report. Miranda has a master's degree in journalism from Syracuse University and is working on her MBA. She also writes about personal finance and investing for her blog "Planting Money Seeds" and contributes to the successful Money Tree Investing Podcast. When not writing about money, Miranda enjoys spending time with her son, traveling, reading, and the outdoors.