You're Almost Out of Time to Make This Key Retirement Savings Move for 2025

By Maurie Backman – Dec 19, 2025 at 1:36PM ESTKey PointsYou only have until Dec. 31 to boost contributions to your 401(k) for 2025.Inform your payroll department at once if you want to increase your contributions before the end of the year.If possible, don't leave any of your employer's match behind. These 10 Stocks Could Mint the Next Wave of Millionaires ›Act immediately, before it's too late.It's hard to believe that 2025 is almost over. But before you know it, you'll be ringing in the new year and trying to remember to write "2026" on all of your medical and financial forms. At this stage of the year, it's important to make sure you've checked off your key financial tasks for 2025. But there's one more move you might still need to make. And if you don't hurry, you might miss your chance. Image source: Getty Images. Don't neglect last-minute contributions to your 401(k) If you're saving for retirement in a tax-advantaged account, you're doing a smart thing. Retirement plans like IRAs and 401(k)s give you a tax break on either your contributions or your withdrawals. If you have an IRA, you can continue making contributions for 2025 up until April 15, 2026 -- next year's tax-filing deadline. But 401(k)s work differently. If you want contributions to your 401(k) plan to count for the 2025 tax year, you need to make them in 2025. Any funds that do not hit your 401(k) by Dec. 31 will not count for the current year.Advertisement So let's say you've only put $4,000 into your 401(k) plan so far, but you were hoping for $6,000 in 2026. If you have the extra $2,000 to contribute, that's the sort of change you need to talk to your payroll department about ASAP. With an IRA, you can simply transfer money into your account when you want to. But 401(k) contributions are taken as payroll deductions, so you can't put the extra money into your account yourself. Rather, someone within your company needs to process that change. That someone may be vacation during the holiday week. Plus, they might needs a few days' notice for that change to go through in time for their payroll run. So it's very important that you notify the right person immediately if you're looking to make a last-minute increase to your 401(k). Try not to leave any workplace matching dollars behind At this point of the year, you may be more inclined to use your extra money for additional holiday gifts, or put it toward a more robust New Year's Eve celebration. But putting additional funds into your 401(k) plan could spell the difference between claiming your company match in full or not. It's a shame to not get your complete 401(k) match, since it's free money for your retirement. So if you're not sure whether to make that last-minute effort or not, figure out if you've maxed out your workplace match. Remember, any money your employer gives you for your 401(k) is money you can invest. So you might think that giving up $200 or $300 in matching dollars is not a big deal. But if you give up that $200 or $300 every year, it could add up to a lot of lost money over time, especially when you consider that investing it all could grow it into a larger sum. An important move you don't want to neglect At this time of the year, there are a lot of last-minute financial moves for people to consider. You may want to complete a Roth conversion before 2025 comes to an end. And if you're a current retiree who's on the hook for taking a required minimum distribution, you'll want to get that done by Dec. 31 to avoid a costly penalty. But if you haven't finished making 401(k) plan contributions for the year, the time to get moving is this minute. You don't want to miss out on being able to boost your savings because you waited too long.Read NextDec 19, 2025 •By Kailey Hagen, CFP3 2026 Medicare Changes Every Retiree Should KnowDec 19, 2025 •By Maurie Backman3 Retirement Investing Mistakes to Avoid in 2026Dec 19, 2025 •By Christy Bieber3 Moves Every Retiree Needs to Make Before the End of 2025Dec 19, 2025 •By Maurie Backman3 Things You and Your Spouse Need to Discuss Before Claiming Social SecurityDec 18, 2025 •By Dana GeorgeWhat Should Retirees Know About Retiring in a Bear MarketDec 18, 2025 •By Kailey Hagen, CFPWant to Max Out Your 401(k) in 2026? Here's What You'll Need to Do.About the AuthorMaurie Backman is a contributing Motley Fool retirement and Social Security expert with more than a decade of experience writing about personal finance, investing, and retirement planning. Maurie previously worked in finance analyzing distressed companies. She studied finance at Binghamton University.TMFBookNerdAdvertisement