Yes, there’s a money move that’s easy to regret if you don’t hit the end of year deadline. This isn’t about flashy investment strategies or get-rich-quick schemes.
It’s about a boring, responsible financial move that Americans will wish they’d made before the calendar flipped: maxing out — or at least significantly increasing — contributions to tax-advantaged accounts before year-end.
Unlike IRA contributions, which can be made until the tax-filing deadline in April, employee contributions to 401(k), 403(b) and 457(b) plans must be completed by Dec. 31. There’s no extension, no grace period, no retroactive adjustments.
For 2025, the 401(k) contribution limit is $23,500 for employee salary deferrals. Workers ages 50 to 59 or 64 and older can contribute an additional $7,500 in catch-up contributions, bringing their total to $31,000. Those between ages 60 and 63 qualify for an enhanced catch-up limit of $11,250, allowing total contributions of $34,750.
Miss the Dec. 31 deadline and those contribution opportunities disappear. You can’t make them up next year because each year has its own separate limit.
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Most Americans aren’t taking full advantage of these retirement vehicles. According to Vanguard’s How America Saves 2025 report, only 14% of participants contributed the annual maximum to their 401(k) last year, despite Americans saving an average of 7.7% of their paychecks in their employer-provided retirement plan — a record high.
The long-term cost of missing these contributions compounds quietly but devastatingly. Assuming a 6% annual return, the difference between contributing $10,000 versus $24,500 over 10 years is about 145% — $132,000 versus $323,000. After 20 years, the person contributing the maximum will have approximately $900,000, while the person contributing $10,000 annually will have just $368,000.
Even more concerning: Research from Empower shows that 25% of workplace savers aren’t contributing enough to maximize their employer match — essentially leaving free money on the table every single paycheck.
The “I’ll start in January” mindset dominates year-end thinking. Life gets busy during the holidays, and increasing retirement contributions feels like something that can wait. But this delay costs real money.
Consider a 35-year-old who skips maximizing contributions for just one year. That $23,500 left on the sidelines, assuming 6% annual growth until age 65, would have grown to approximately $134,000. Skip five years of maximum contributions throughout a career, and you’re looking at well over a half-million dollars in lost retirement savings.
