Year-End Tax Planning Guide 2026

The best time to start planning for your 2026 taxes is not April. It is right now. The decisions you make before December 31 determine what you owe in April, and the difference between a reactive and proactive approach is often tens of thousands of dollars.

Here are the strategies that have the biggest impact for business owners and high-income professionals, along with the deadlines you cannot afford to miss.

1. Section 179 Expensing

Section 179 lets you deduct the full purchase price of qualifying equipment and software in the year you buy it, instead of depreciating it over several years.

2026 Limits:

• Maximum deduction: $1,250,000 (estimated, adjusted for inflation)
• Phase-out threshold: $3,130,000 in total equipment purchases
• Qualifying items: computers, office furniture, vehicles over 6,000 lbs GVWR, machinery, software

Strategy: If you need equipment for your business, buying it before December 31 lets you take the full deduction on your 2026 return. This is one of the most straightforward ways to reduce your taxable income.

Common mistake: Buying equipment you do not actually need just for the deduction. A $50,000 purchase only saves you $12,000-$18,500 in taxes (depending on your bracket). You are still spending $31,500-$38,000 you did not need to spend.

Deadline: Equipment must be placed in service by December 31, 2026.

2. Maximize Retirement Contributions

Retirement accounts are the most reliable way to reduce your taxable income while building wealth.

2026 Contribution Limits (estimated):

| Account | Limit | Catch-up (50+) | |---------|-------|-----------------| | 401(k) / Solo 401(k) employee deferral | $23,500 | +$7,500 | | SEP-IRA (employer contribution) | 25% of compensation, up to $70,000 | — | | Traditional IRA | $7,000 | +$1,000 | | SIMPLE IRA | $16,500 | +$3,500 | | HSA (family) | $8,550 | +$1,000 |

Strategy for business owners: A Solo 401(k) is often the best option if you are self-employed with no employees. You can contribute as both the employee (up to $23,500) and the employer (up to 25% of net self-employment income), potentially sheltering over $60,000 from taxes.

SEP-IRA advantage: You have until your tax filing deadline (including extensions) to set up and fund a SEP-IRA for 2026. But do not wait - establishing it before year-end gives you more flexibility.

Deadline: 401(k) employee deferrals must be made by December 31. Employer contributions and SEP-IRAs can be funded until the tax filing deadline (April 15, 2027, or October 15 with extension).

3. S-Corp Election Timing

If you are operating as a sole proprietor or single-member LLC and your net business income exceeds $60,000, electing S-Corp status can save you thousands in self-employment taxes.

Key deadline: To have S-Corp status for 2027, you must file Form 2553 by March 15, 2027. But year-end is when you should be evaluating whether it makes sense, so you are ready to act.

What to evaluate now:

• Your projected 2026 net business income
• The cost of running payroll (typically $2,000-$5,000/year)
• Your reasonable salary amount
• Whether your income is stable enough to justify the added complexity

If you missed the March 15 deadline for 2026, you may still be able to make a late election by demonstrating reasonable cause. Talk to your tax professional about your options.

4. Defer Income / Accelerate Expenses

This classic strategy works if you expect to be in the same or lower tax bracket next year.

Defer income:

• Delay invoicing in December until January (for cash-basis businesses)
• Push bonus payments to January
• Delay closing a sale until the new year

Accelerate expenses:

• Prepay January rent in December
• Stock up on supplies you will need in Q1
• Pay outstanding vendor invoices before year-end
• Make planned charitable contributions before December 31

Important: This strategy reverses if you expect to be in a higher tax bracket next year. In that case, you would want to accelerate income and defer expenses.

5. Qualified Business Income (QBI) Deduction

The Section 199A deduction allows eligible business owners to deduct up to 20% of their qualified business income. For a business owner with $200,000 in QBI, that is a $40,000 deduction.

Phase-out thresholds for 2026 (estimated):

• Single: $191,950 - $241,950
• Married filing jointly: $383,900 - $483,900

Strategy: If you are near the phase-out range, reducing your taxable income through retirement contributions or other deductions can keep you under the threshold and preserve the full QBI deduction. The math on this is significant - losing the QBI deduction on $200,000 of income costs you $40,000 in deductions.

Specified service businesses (healthcare, law, consulting, financial services) face additional restrictions above the phase-out thresholds. If you are in one of these fields, planning around the QBI thresholds is especially important.

6. Health Savings Account (HSA) Contributions

If you have a high-deductible health plan (HDHP), your HSA is a triple tax advantage: tax-deductible contributions, tax-free growth, and tax-free withdrawals for qualified medical expenses.

2026 Limits (estimated):

• Individual: $4,300
• Family: $8,550
• Catch-up (55+): additional $1,000

Strategy: Max out your HSA even if you do not have current medical expenses. After age 65, you can withdraw HSA funds for any purpose (you just pay income tax, like a traditional IRA). It is an extra retirement account that also covers healthcare.

Deadline: You have until April 15, 2027 to make HSA contributions for the 2026 tax year.

7. Charitable Giving Strategies

If you itemize deductions, charitable contributions can significantly reduce your tax bill.

Strategies to consider:

• Donor-advised fund (DAF): Bunch multiple years of charitable giving into one year to exceed the standard deduction threshold. You get the full deduction now and distribute the funds to charities over time.
• Donate appreciated stock: If you have stocks with large unrealized gains, donating them directly to charity lets you deduct the full market value without paying capital gains tax.
• Qualified charitable distribution (QCD): If you are 70.5 or older, you can donate up to $105,000 directly from your IRA to charity. It counts toward your required minimum distribution but is excluded from taxable income.

Deadline: December 31, 2026 for all charitable deductions.

8. Review Your Estimated Tax Payments

If you are self-employed or have significant income outside of W-2 wages, check whether you have paid enough in estimated taxes to avoid the underpayment penalty. Keeping clean books and records throughout the year makes this review much easier.

Safe harbor rules: You owe no penalty if you have paid at least:

• 90% of your 2026 tax liability, OR
• 100% of your 2025 tax liability (110% if your 2025 AGI exceeded $150,000)

If you are short, make an additional estimated payment before January 15, 2027 (the Q4 deadline).

9. Harvest Investment Losses

If you have taxable investment accounts with unrealized losses, selling those positions before year-end lets you offset capital gains and up to $3,000 of ordinary income.

Watch out for the wash sale rule: If you buy the same or "substantially identical" security within 30 days before or after the sale, the loss is disallowed. Wait 31 days before repurchasing, or buy a similar (but not identical) investment in the meantime.

Key 2026 Deadlines

| Date | Action | |------|--------| | December 31, 2026 | Section 179 equipment in service | | December 31, 2026 | 401(k) employee deferrals | | December 31, 2026 | Charitable contributions | | December 31, 2026 | Income deferral / expense acceleration | | January 15, 2027 | Q4 estimated tax payment | | March 15, 2027 | S-Corp/Partnership returns due | | March 15, 2027 | S-Corp election (Form 2553) for 2027 | | April 15, 2027 | Individual returns due | | April 15, 2027 | SEP-IRA / HSA contributions for 2026 | | October 15, 2027 | Extended individual returns due |

The Cost of Waiting

Every strategy on this list requires time to evaluate, plan, and execute. Waiting until January means most of these options are off the table.

The business owners who save the most in taxes are the ones who plan throughout the year, not just at filing time. A proactive tax planning session in Q3 or Q4 consistently saves our clients $10,000 to $50,000 or more compared to reactive filing.

Not sure where you stand? Try our free savings estimator to see how much you could save before year-end.

Ready to build your year-end tax plan? Book a free consultation and we will walk through the strategies that apply to your specific situation.