5 Year-End Money Moves to Make Before December 31 (With Real Numbers)

I used to treat December like a vacation from money. The year was basically over, the holidays were happening, and I'd deal with everything in January. Then one year I did the actual math on what that cost me: an untouched 401(k) limit, a forfeited FSA balance, and January credit card debt that took until April to clear. It was the most expensive "I'll deal with it later" I'd ever told myself.

Here's the framework I use now. Call it the December 31 rule: some of your money has a hard deadline, and every dollar you move before the calendar flips is worth more than the same dollar in January. IRS deadlines, account rules, and your own spending calendar all converge in Q4. You don't need a finance degree. You need a checklist and about one afternoon.

Move 1: Top up your 401(k) while you still can

The IRS has set the 2026 employee contribution limit for 401(k), 403(b), and most 457 plans at $24,500, up $1,000 from $23,500 in 2025, according to the IRS announcement of Notice 2025-67. If you're 50 or older, the catch-up contribution rises to $8,000 (up from $7,500), for a total of $32,500.

Here's why that matters before December 31: your 2026 limit is locked to 2026 contributions. Unused room doesn't roll over, and you can usually adjust your contribution rate through your benefits portal in minutes. If you earn $80,000 and bump your contribution rate for the remaining paychecks to hit the max, every extra $1,000 you contribute in a traditional 401(k) cuts your taxable income by $1,000. At a 22% federal bracket, that's roughly $220 in tax savings per $1,000 — my math, using current brackets. Three years ago I realized I'd been leaving $4,000 of contribution room on the table every December. That was nearly $900 in unnecessary taxes per year. Now I check my year-to-date contributions in October and set the dial to finish strong.

Move 2: Spend down your FSA before the money evaporates

Flexible spending accounts are the cruelest account in personal finance: the IRS lets you contribute up to $3,400 in 2026 (up from $3,300, per IRS Revenue Procedure 2025-32 via Mercer), and most plans are use-it-or-lose-it. Your employer can allow a carryover of up to $680 into next year, or a short grace period — but not both, and anything above the carryover cap simply vanishes on December 31.

At a 22% bracket plus payroll taxes, $3,400 of pre-tax FSA contributions saves you roughly $1,000 in taxes (my math). Forfeiting even $500 of unspent FSA money because you forgot is like mailing your tax savings back. I log into my FSA portal in early December, check the balance, and schedule the things I'd be paying for anyway: an eye exam, new glasses, a dentist visit, a first-aid kit refill, sunscreen. Every one of those is FSA-eligible under IRS rules, and every one beats forfeiture.

Move 3: Park your cash at today's rates before they move

The Federal Reserve raised its benchmark rate by 25 basis points at its September 2026 meeting, its first hike since 2023, according to The Wall Street Journal, and most Fed officials expect at least one more increase this year. Savings rates are responding: as of September 28, 2026, the best high-yield savings accounts pay up to 4.50% APY, per Motley Fool's daily rate survey. Meanwhile the average savings account still pays just 0.38%, per FDIC data cited by the Journal.

Do the math on that gap: $10,000 at 4.50% earns $450 a year; at 0.38% it earns $38. That's a $412 difference per year for moving your emergency fund to a different bank account — about thirty minutes of work. I keep my emergency fund in a high-yield account and check rates once a quarter. With the Fed hiking again, this is a rare moment when patience on cash is actually rewarded, and I'd rather lock in today's rates than wonder in March where 4% went.

Move 4: Put a hard number on your holiday spending now

The National Retail Federation's 2025 holiday survey, conducted by Prosper Insights & Analytics, projected average per-person holiday spending of $890.49 — the second-highest in the survey's 23-year history — with $627.93 of that going to gifts for family and friends. Separate post-holiday data from ICSC found that 43% of shoppers stayed on budget and 13% spent less than planned — meaning a majority managed it fine, and the difference was having a plan.

My system is embarrassingly simple and it works. I take the $627.93 gift figure as a baseline, adjust for my own family size, write down every person I'm buying for with a dollar amount next to each name, and sum it. If the sum is bigger than my number, I cut items — not budgets. Cutting an item is a decision; cutting a budget is a fantasy. I do this in early October, before the first sale email arrives, because 85% of shoppers told the NRF they expect tariffs to push prices higher, and retailers count on panic. A list made in October beats a cart filled in December.

FAQ

What's the 401(k) contribution limit for 2026? $24,500 for employee contributions to 401(k), 403(b), and most 457 plans, up $1,000 from 2025, per the IRS (Notice 2025-67). If you're 50 or older, the catch-up contribution is $8,000, for a total of $32,500.

What happens to unused FSA money at the end of the year? Most FSAs are use-it-or-lose-it. Your employer may allow a carryover of up to $680 for 2026 plans (20% of the $3,400 IRS contribution limit) or offer a short grace period, but not both. Anything beyond that is forfeited on December 31.

How much can I earn on a high-yield savings account right now? As of September 28, 2026, top accounts pay up to 4.50% APY, per Motley Fool. The average savings account pays 0.38%, per the FDIC. On a $10,000 balance, that's $450 versus $38 a year.

How much do Americans spend on the holidays? The National Retail Federation projected $890.49 per person for the 2025 season, with $627.93 going to gifts. Use that as a baseline, list every recipient with a dollar amount, and cut items — not budgets — until the sum fits.