Year-End Tax Moves 2026 — 12 Actions to Take Before December 31

The Year-End Tax Deadline Problem

Most tax advice is about what to do when filing. The problem: by April 15, nearly every strategy window is closed. The moves that actually reduce your tax bill have to happen by December 31.

Here are 12 actions ranked by dollar impact.

Move 1 — Max Your 401(k) (Deadline: December 31)

Potential savings: $5,520 at 24% bracket

The 2026 contribution limit is $23,000 ($30,500 if you're 50+). Every dollar contributed reduces your taxable income dollar-for-dollar.

If you're behind: Check your current contribution rate in your HR portal and increase the percentage now. Most payroll systems process changes within 1-2 pay periods.

The math: Contributing an additional $5,000 at a 24% marginal rate saves $1,200 in federal taxes alone, plus any state income tax.

Move 2 — Harvest Investment Losses (Deadline: December 31)

Potential savings: $1,000-$5,000+ depending on portfolio

If you have positions in your taxable brokerage account that are down from your purchase price, sell them before year-end. The realized losses offset:

1. Capital gains (dollar-for-dollar)
2. Ordinary income (up to $3,000/year)
3. Carry forward indefinitely to future years

Wash-sale rule: You can't repurchase the same or substantially identical security within 30 days before or after the sale. Swap into a similar (but not identical) ETF to maintain market exposure — e.g., sell VTI and buy SCHB.

Use our Tax-Loss Harvesting Calculator to see your exact savings.

Move 3 — Max Your HSA (Deadline: April 15, but fund now)

Potential savings: Triple tax advantage

If you have a high-deductible health plan (HDHP), the HSA is the best account in the tax code — contributions are pre-tax, growth is tax-free, and withdrawals for medical expenses are tax-free.

2026 limits: $4,300 individual / $8,550 family (+$1,000 catch-up if 55+). Unlike 401(k)s, you can contribute directly to your HSA until April 15, 2027 and deduct it on your 2026 return. But fund it now to maximize investment time.

Move 4 — Consider a Roth Conversion (Deadline: December 31)

Potential savings: Tens of thousands tax-free over time

A Roth conversion makes sense when:

• Your income is unusually low this year (career break, early retirement gap year)
• You're in a lower bracket than you expect in retirement
• You have significant traditional IRA / rollover IRA balances

Convert only enough to fill up your current bracket without jumping to the next. For example, if you're in the 22% bracket ($47,151-$100,525 for single filers in 2026) and your income is $75,000, you could convert up to ~$25,000 and stay in the 22% bracket.

Move 5 — Accelerate Deductions Into This Year (Deadline: December 31)

Potential savings: $500-$3,000 if you itemize

If you itemize deductions and expect similar or lower income next year, accelerating deductible expenses into 2026 reduces this year's tax bill:

• Make your January mortgage payment in December
• Pay state/local taxes due in Q1 2027 early
• Bunch charitable donations (give 2 years' worth this December)

Caution: This only helps if your total deductions exceed the standard deduction ($14,600 single / $29,200 married in 2026).

Move 6 — Max Your IRA (April 15 deadline, but start now)

Potential savings: $1,540 at 22% bracket (traditional)

2026 IRA limit: $7,000 ($8,000 if 50+). Traditional IRA contributions may be deductible depending on income and whether you have a workplace plan.

Even if not deductible, contribute to a Roth IRA if eligible (income under $146K single / $230K married) for tax-free growth.

Move 7 — Use Your Flexible Spending Account (FSA) (Deadline: December 31 for most plans)

Potential savings: Avoid losing your own money

FSA funds are "use it or lose it" for most plans (some allow a $640 rollover or 2.5-month grace period — check your plan). If you have unspent FSA funds, use them on eligible expenses before year-end:

• Glasses, contacts, or LASIK
• Dental procedures
• Medical equipment
• Over-the-counter medications

Move 8 — Take Required Minimum Distributions (Deadline: December 31)

Penalty: 25% of the missed RMD amount

If you're 73 or older, you must take RMDs from traditional IRAs and 401(k)s by December 31 (first-year exception: April 1 of the following year). Missing an RMD triggers a 25% excise tax on the shortfall, reduced to 10% if corrected quickly.

Calculate your RMD at irs.gov using the Uniform Lifetime Table and your December 31 prior-year balance.

Move 9 — Fund a 529 for State Tax Deductions (December 31 for most states)

Potential savings: $350-$1,100 depending on state

If your state offers a 529 deduction, contribute before December 31. You don't have to invest — you can contribute and move to a stable value fund the same day. The deduction alone may justify it.

Top states by deduction value: New York ($5K/$10K deduction), Illinois ($10K/$20K), Virginia ($4K unlimited), Indiana (20% tax credit up to $1,500).

Move 10 — Donate Appreciated Stock (Deadline: December 31)

Potential savings: Avoid capital gains + get full deduction

Instead of donating cash to charity, donate appreciated shares directly. You get a deduction for the full fair market value and never pay capital gains tax on the appreciation. The charity sells the shares tax-free.

Example: You own $5,000 of stock you bought for $1,000. Donating it directly vs. selling and donating cash saves you the capital gains tax on $4,000 of appreciation — roughly $600 at the 15% long-term rate.

Move 11 — Check Your Withholding

Potential savings: Avoid a surprise tax bill or underpayment penalty

Use the IRS Tax Withholding Estimator at irs.gov to verify you're on track for the year. If you owe significantly more than expected, you can increase withholding on your last paycheck(s) of the year. Withholding from wages can be applied to any quarter retroactively, unlike estimated tax payments.

Move 12 — Review Beneficiary Designations

Potential savings: Avoids probate costs and ensures correct asset transfer

This isn't a tax move per se, but year-end is the right time to confirm retirement account, life insurance, and brokerage beneficiary designations are current — especially after major life events (marriage, divorce, birth, death). Outdated beneficiaries can override your will and create significant estate issues.

The Year-End Checklist

• Increase 401(k) contribution to hit $23,000 limit
• Review taxable portfolio for loss-harvesting opportunities
• Contribute to HSA if HDHP-enrolled
• Evaluate Roth conversion opportunity
• Use FSA balance before year-end
• Take RMD if 73+
• Make 529 contribution for state deduction
• Donate appreciated stock instead of cash
• Check withholding status
• Update beneficiary designations

Related Tools

• Tax-Loss Harvesting Calculator — Model your exact savings
• Roth vs Traditional IRA Calculator — Compare conversion math
• 401(k) vs Roth 401(k) Calculator — Pre-tax vs post-tax analysis
• Tax Bracket Calculator — Know your marginal rate before you act