Year End Tax Planning: 12 Moves to Make Before December 31

Tax season starts in your mind on April 15, but the real deadline for most money-saving strategies is December 31. That mismatch is costly. Once the calendar flips to January, you lose the ability to increase 401(k) contributions, harvest investment losses, accelerate deductions, or make Roth conversions for the prior year. By the time you sit down with tax software, or a CPA, the window has already closed.

Year end tax planning is the practice of reviewing your income, deductions, investments, and retirement accounts in the final weeks of the year and taking deliberate action to lower your tax bill. It matters whether you earn $60,000 or $600,000, and whether you're a W-2 employee or self-employed. The specific moves differ, but the principle is the same: the tax code rewards people who act before the deadline, not after.

This guide walks through 12 concrete actions ranked roughly by dollar impact. Each move includes the hard deadline, who it applies to, and the math behind the savings. If you're deciding between tackling all 12 or just the top few, start with the first four: they account for the majority of potential savings for most households. This is especially important if you're someone who has historically waited until filing season to think about taxes and ended up leaving money on the table.

Use the Tax Bracket Calculator to know your current marginal rate before working through any of these moves.

Year End Tax Planning Strategies Ranked by Dollar Impact

The table below summarizes all 12 moves so you can quickly identify which ones apply to your situation. We'll break each one down in the sections that follow.

Dollar-Impact Ladder by Income Level

Your marginal tax bracket determines how much each dollar of deductions is actually worth. Here is a rough guide:

• $10,000 in deductions at the 12% bracket: saves $1,200 in federal tax
• $10,000 in deductions at the 22% bracket: saves $2,200 in federal tax
• $10,000 in deductions at the 24% bracket: saves $2,400 in federal tax
• $10,000 in deductions at the 32% bracket: saves $3,200 in federal tax
• $10,000 in deductions at the 35% bracket: saves $3,500 in federal tax

State income taxes stack on top. A California resident in the 9.3% state bracket saves an additional $930 per $10,000 of deductions, for example.

How to Execute Your Year End Tax Plan in 3 Phases

A checklist is only useful if you actually work through it. Here is a numbered action plan to follow between now and December 31.

1. Audit your current position (week 1). Pull your latest pay stub to see year-to-date 401(k) contributions, review your brokerage account for unrealized losses, check your HSA and FSA balances, and run the IRS Tax Withholding Estimator to see if you're on track. Log into your HR portal and note how many pay periods remain.

2. Model the biggest moves (week 2). Use the Roth vs Traditional IRA Calculator to evaluate whether a Roth conversion makes sense this year. Use our Tax-Loss Harvesting Calculator to quantify exactly how much selling losing positions would save. Estimate your total itemized deductions to see if bunching charitable donations pushes you past the standard deduction threshold.

3. Execute and document (weeks 3–4). Increase your 401(k) percentage through payroll, sell harvested positions and immediately reinvest in non-identical funds (respecting the 30-day wash-sale window), fund your HSA, and make any planned charitable contributions. Save confirmations and receipts in a dedicated tax folder; your future self will thank you at filing time.

This phased approach prevents last-minute scrambling and ensures you don't accidentally trigger the wash-sale rule or miss a payroll deadline.

The Big Four Moves: Detailed Breakdown

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

The 2026 contribution limit is $24,500 ($32,000 if you're 50 or older). Every dollar contributed reduces your taxable income dollar-for-dollar if you use the traditional (pre-tax) option.

Consider a household: Maria, 34, single, earning $85,000. She has contributed $15,000 year-to-date. With three pay periods left, she can increase her contribution rate to funnel the remaining $8,000 into her 401(k). At the 22% federal bracket, that saves her $1,760 in federal taxes, plus roughly $400 in state taxes if she lives in a state like Colorado (4.4% flat rate). Total savings: roughly $2,160 from a single payroll adjustment.

If you're behind, check your current contribution rate in your HR portal and increase the percentage now. Most payroll systems process changes within one to two pay periods.

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

Move 2: Harvest Investment Losses - Deadline: December 31

If you hold positions in a taxable brokerage account that have dropped below your purchase price, selling them before year-end creates a realized loss. Those losses offset:

1. Capital gains dollar-for-dollar
2. Ordinary income up to $3,000 per year
3. Remaining losses carry forward indefinitely to future years

Wash-sale rule: You cannot 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. For example, sell VTI and buy SCHB.

For example, David and Lin, married filing jointly, have $12,000 in unrealized losses in a total stock market fund and $8,000 in realized gains from selling a single stock earlier this year. By harvesting the $12,000 loss: $8,000 offsets the realized gains (saving roughly $1,200 at the 15% long-term capital gains rate), $3,000 offsets ordinary income (saving $720 at the 24% bracket), and the remaining $1,000 carries forward. Total first-year savings: approximately $1,920.

Use the Tax-Loss Harvesting Calculator to model your exact numbers.

Move 3: Max Your HSA - Deadline: April 15 (But Fund Now)

If you have a high-deductible health plan (HDHP), the health savings account is the single most tax-efficient account in the code: contributions are pre-tax, growth is tax-free, and withdrawals for qualified medical expenses are tax-free.

2026 limits: $4,400 individual / $8,750 family (+$1,000 catch-up if 55 or older). Unlike 401(k) contributions, you can contribute directly to your HSA until April 15, 2027 and deduct it on your 2026 return. But funding now maximizes investment time. Many HSA providers let you invest balances above a cash threshold into index funds, giving the account long-term compounding potential similar to an IRA. See the IRS HSA guidelines for eligibility details.

Move 4: Evaluate a Roth Conversion - Deadline: December 31

A Roth conversion means moving money from a traditional IRA or rollover IRA into a Roth IRA. You pay ordinary income tax on the converted amount now, but all future growth and withdrawals come out tax-free.

A Roth conversion makes sense when:

• Your income is unusually low this year (career break, sabbatical, early retirement gap year)
• You expect to be in a higher bracket in retirement
• You have significant traditional IRA or rollover IRA balances you want to shield from future RMDs

Convert only enough to fill up your current bracket without jumping to the next. For example, if you're single in the 22% bracket ($47,151–$100,525 for 2026) and your taxable income is $75,000, you could convert up to roughly $25,000 and stay within that bracket. Use the Roth vs Traditional IRA Calculator to model the long-term math.

Year End Tax Planning: Choose the Right Path for Your Situation

Not every move fits every taxpayer. Here is a decision framework to guide your year end tax planning priorities:

Choose the "maximize deductions now" path if:

• You're in a high bracket this year and expect a lower bracket next year
• You itemize deductions or are close to the threshold
• You have bunching opportunities for charitable donations
• You're employed and can increase 401(k) contributions immediately

Choose the "shift income to tax-free accounts" path if:

• You're in a lower bracket this year than you expect in the future
• You have large traditional IRA balances and a long time horizon
• You're in an early retirement gap year or on sabbatical
• You want to reduce future required minimum distributions

Many people benefit from both paths simultaneously. The key question: is your income unusually high this year (favor deductions) or unusually low (favor Roth conversions)?

If you're deciding between a Roth conversion and maxing a 401(k), the answer for most W-2 workers is to do both: the 401(k) reduces current taxable income, and a partial Roth conversion fills unused space in your current bracket. The 401(k) vs Roth 401(k) Calculator can help you compare the pre-tax versus post-tax tradeoff.

Additional Year End Tax Moves Worth Your Attention

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

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

• Make your January mortgage payment in December
• Pay state or local taxes due in Q1 2027 early (subject to the $10,000 SALT cap)
• Bunch charitable donations: give two years' worth this December

Caution: This only helps if your total deductions exceed the standard deduction ($14,600 single / $29,200 married filing jointly in 2026). If you're within a few hundred dollars of the threshold, bunching donations can push you over and unlock the benefit.

Move 6: Max Your IRA (April 15 Deadline, But Start Now)

The 2026 IRA limit is $7,000 ($8,000 if 50 or older). 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 $146,000 single / $230,000 married) for tax-free growth. Read our guide on choosing the right IRA type for a deeper comparison.

Move 7: Use Your FSA Balance (December 31 for Most Plans)

FSA funds are "use it or lose it" for most plans (some allow a $640 rollover or 2.5-month grace period, so 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 (December 31)

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 promptly under SECURE 2.0 rules.

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)

If your state offers a 529 deduction, contribute before December 31. You don't have to invest aggressively; you can contribute and park the money in a stable value fund the same day. The state deduction alone may justify the contribution.

Top states by deduction value: New York ($5,000/$10,000 deduction), Illinois ($10,000/$20,000), Virginia ($4,000 unlimited contributions), Indiana (20% tax credit up to $1,500).

Move 10: Donate Appreciated Stock (December 31)

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

For example, you own $5,000 of stock you bought for $1,000. Donating it directly versus selling and donating cash saves you the capital gains tax on $4,000 of appreciation, roughly $600 at the 15% long-term capital gains rate. This strategy works best when you hold highly appreciated shares you've owned for more than a year.

Move 11: Check Your Withholding

Use the IRS Tax Withholding Estimator to verify you're on track for the year. If you owe significantly more than expected, you can increase withholding on your last paychecks of the year. Withholding from wages can be applied to any quarter retroactively, unlike estimated tax payments, a valuable quirk that can help you avoid underpayment penalties.

Move 12: Review Beneficiary Designations

This is not a tax move per se, but year-end is the right time to confirm that retirement account, life insurance, and brokerage beneficiary designations are current, especially after major life events such as marriage, divorce, birth, or death. Outdated beneficiaries can override your will and create significant estate complications. The Consumer Financial Protection Bureau has a helpful primer on how beneficiary designations work.

The Marketing Hook vs. Long-Term Reality

Many financial firms run year-end campaigns touting "free tax savings" or "one simple trick to cut your tax bill." The flashy hook is usually a narrow move, like opening a new IRA with a bonus or making a last-minute charitable donation, presented as a silver bullet. The reality is that no single move replaces a comprehensive year end tax planning review.

A $250 IRA bonus sounds appealing, but if you overlook $3,000 in harvestable losses or leave $8,000 of 401(k) space unused, you've traded a small reward for a much larger missed opportunity. The long-term math always favors the boring, systematic approach: run the numbers, prioritize by dollar impact, and execute across all applicable strategies rather than chasing a single promotional offer.

Similarly, "zero tax" Roth conversion stories circulating online often omit that the person had an unusually low income year, large losses to offset, or specific state circumstances. Conversions are powerful but context-dependent. Always model your own numbers before acting.

Pros and Cons of Aggressive Year End Tax Planning

Where This Approach Wins (Pros)

• Immediate cash savings. Reducing taxable income by $10,000 at the 24% bracket puts $2,400 back in your pocket this year.
• Compounding benefit. Tax savings invested now grow for decades. The earlier you harvest losses or convert to Roth, the more time you gain.
• Reduced future tax liability. Roth conversions and HSA contributions create pools of money that will never be taxed again.
• Loss carryforward flexibility. Harvested losses above the $3,000 annual limit carry forward indefinitely, creating a tax asset for future years.

Where It Falls Short (Cons)

• Complexity and time commitment. Coordinating 401(k) increases, brokerage sales, and Roth conversions in a compressed timeframe is stressful.
• Risk of mistakes. Wash-sale violations, over-conversion into a higher bracket, or miscounting FSA grace periods can backfire.
• Upfront cash requirement. Roth conversions create a tax bill due in April. You need liquid funds to cover the taxes without raiding the converted amount.
• Not all moves apply universally. If you take the standard deduction, several of these strategies (bunching, SALT acceleration) offer no benefit.
• Opportunity cost. Time spent optimizing taxes is time not spent on other financial priorities. Focus on the highest-impact moves first.

Year End Tax Savings Across Balance Tiers

The total potential savings from year end tax planning depends on your income, account balances, and marginal rate. Here is a rough dollar-impact ladder for a filer in the 24% federal bracket, as of June 2026:

401(k) savings assume $24,500 max contribution at 24%. Loss harvest assumes 10–30% of the portfolio is in a loss position. HSA benefit assumes $4,400 individual contribution at 24%.

These numbers exclude state tax savings, which can add 3–10 points of additional benefit depending on where you live.

Keeping your tax savings in a high-yield account while you plan next steps makes sense. Current top high-yield savings rates sit near 4.20%, dramatically above the 0.38% national average. Parking your tax refund or freed-up cash in a competitive account, rather than a traditional bank paying near zero, is a simple way to earn more on money you've already saved. Compare options on our high-yield savings page or explore CD rates if you can lock up funds for a set term.

Methodology

SwitchWize ranks year end tax planning strategies by verified dollar impact using current IRS contribution limits, published tax brackets, and standard capital gains rates. We cross-reference deadlines against IRS publications and update limits annually. Product rates and comparisons on our site are verified against institution disclosures as described on our methodology page.

This is educational information, not personalized financial advice. Consult a qualified tax professional before making decisions based on your specific situation.