Year-end tax checklist
8 tax moves to make before December 31
Most tax decisions feel irreversible after the year closes — but the window to act is open until December 31. This checklist walks through eight moves that can reduce your current-year tax bill, avoid penalties, or set up a better position for next year. Some steps take five minutes; others require a phone call to your brokerage or HR department. Run through it in October or November while there are still pay periods left to adjust.
These are calculator-based estimates, not tax advice. Your actual situation may differ — especially for RMDs, Roth conversions, and tax-loss harvesting, which have specific rules. Consult a tax professional before making large moves. Your progress is saved in this browser — bookmark the page and come back if you need to.
When to work through this checklist
October or November is ideal — you have a full picture of the year's income and there are still pay periods left to raise 401(k) deferrals or add withholding. December still works for most steps, but payroll changes submitted late may not take effect until January.
Skip any step that doesn't apply. Each step opens a full calculator where you can save scenarios in your browser.
0 of 8 complete
Steps you skip can be checked off without opening the calculator.
Checklist steps
Step 1 of 8
Maximize (or increase) your 401(k) contribution
The 2026 401(k) limit is $24,500 ($32,500 with catch-up). If you won't hit the limit, increasing your deferral rate now applies to the remaining pay periods of the year. Every uncontributed dollar is an after-tax dollar. Separate IRA contributions ($7,500 for 2026) can still be made until the April tax deadline.
Open 401(k) calculator →Step 2 of 8
Max out your HSA if you have one
HSA contributions must be made before December 31 to reduce this year's taxable income through payroll, but you can also contribute directly until the April 15 tax deadline. The 2026 limit is $4,400 (self-only) or $8,750 (family). HSA contributions are the only triple-tax-advantaged move available.
Open HSA calculator →Step 3 of 8
Harvest tax losses to offset capital gains
If you have taxable investment accounts with positions currently worth less than you paid, selling before December 31 locks in a capital loss that can offset capital gains — or up to $3,000 of ordinary income if losses exceed gains. Losses carry forward indefinitely if unused. Watch the 30-day wash-sale rule.
Open capital gains calculator →Step 4 of 8
Take your Required Minimum Distribution (RMD)
If you are 73 or older, you must take your 2026 RMD from tax-deferred accounts by December 31 — or face a 25% excise tax on the amount not withdrawn. First-year RMDs may be delayed to April 1 of the following year, but taking two RMDs in one year increases taxable income.
Open RMD calculator →Step 5 of 8
Estimate your Roth conversion opportunity
The window for a 2026 Roth conversion closes December 31. If your income this year is lower than usual — due to a gap in employment, retirement, or large deductions — this may be a good year to convert traditional IRA funds to Roth at a lower tax rate. Consider IRMAA impacts two years out.
Open Roth conversion calculator →Step 6 of 8
Check your withholding to avoid an underpayment penalty
If you have side income, investment gains, or a life change (marriage, divorce, new job) and have not adjusted your W-4 or made estimated payments, you may owe an underpayment penalty in April. Run your income tax estimate now while there are still pay periods left to add extra withholding.
Open W-4 withholding calculator →Step 7 of 8
Time charitable contributions for maximum tax benefit
Cash donations to qualified charities are deductible if you itemize. If your itemized deductions are near the standard deduction threshold, bunching two years of giving into December may push you over. If you are 70½ or older, a Qualified Charitable Distribution (QCD) from your IRA counts toward your RMD and is excluded from income — up to $105,000 in 2026.
Open income tax estimator →Step 8 of 8
Use your Health FSA balance before it expires
Health FSA funds are generally use-it-or-lose-it by December 31 (or March 15 if your plan has a grace period, or up to $660 carryover if your plan allows it). Schedule eligible medical, dental, and vision expenses now — glasses, orthodontia, prescriptions — before unused funds are forfeited.
See 2026 FSA contribution limits →
Frequently asked questions
When should I run this checklist?
October or November is ideal — you have a full picture of your year's income and there are still pay periods left to adjust 401(k) contributions or withholding. December works for most steps, but some (like 401(k) payroll changes) may not take effect until January if submitted too late.
What if I miss the December 31 deadline?
Some moves have a hard December 31 cutoff: 401(k) contributions (payroll must process in time), RMDs, tax-loss harvesting, FSA spending, and Roth conversions. Others — IRA contributions and HSA direct contributions — can be made until April 15 of the following year and still count for the current tax year.
Do I need to do all 8 steps?
No. Skip steps that don't apply — RMDs only matter if you're 73 or older, FSA only if you have a health FSA, tax-loss harvesting only if you have taxable investment accounts with losses. Check off skipped steps to track what you've reviewed.
Is this financial or tax advice?
No. This checklist links to calculators that provide estimates. Roth conversions, RMDs, and tax-loss harvesting in particular have complex rules — consult a CPA or tax advisor before making significant moves.
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