The 2026 Year-End Tax Checklist: 14 Moves to Make Before December 31

The tax year closes on December 31, and with it most of the levers that can reduce what you owe. A disciplined year-end review is the single most valuable tax-planning habit you can build.

Max out retirement contributions. The deadline for 401(k) contributions is December 31; IRA contributions can be made until the filing deadline, but funding now captures a full year of compounding.

Harvest investment losses to offset gains. Reviewing your portfolio for underperforming positions and selling them to offset realized gains can eliminate or reduce capital gains tax. Mind the wash-sale rule, which disallows a loss if you repurchase the same security within 30 days.

Make charitable contributions. Donations made by December 31 are deductible for the current year. Bunching several years of giving into one year can help you exceed the standard deduction threshold.

Spend down FSA funds. Flexible spending account balances may be forfeited at year-end depending on your plan's rules. Schedule eligible medical appointments and purchases now.

Defer or accelerate income. If you expect to be in a lower bracket next year, deferring a bonus or invoice into January reduces this year's taxable income. The reverse applies if next year's rate will be higher.

Review your withholding and estimated payments. A final quarterly check ensures you meet safe-harbor thresholds and avoid underpayment penalties.

Time major purchases for depreciation. Equipment and qualifying property placed in service by December 31 may be eligible for immediate expensing or bonus depreciation.

Confirm your entity election. S-Corp and other elections have filing deadlines; missing them delays the benefit by an entire tax year.

The common thread is timing. Every move on this list is ordinary and available — but only if it happens before the ball drops.