The QBI Deduction Explained: How Small Business Owners Cut Their Tax Bill by 20%

June 26, 2026 · Guide · 10 min read

The Section 199A qualified business income (QBI) deduction lets eligible pass-through business owners deduct up to 20% of their net business income from federal taxable income — not as a business expense, but as a personal deduction. For a sole proprietor netting $200,000, that is a potential $40,000 deduction before a single other strategy is applied. Originally set to expire after 2025 under the Tax Cuts and Jobs Act, the deduction was extended through 2026 legislation; verify the current status with a CPA since tax law continues to evolve.

Who Qualifies for the QBI Deduction

The deduction is available to owners of pass-through entities — businesses whose income flows through to the owner's personal tax return rather than being taxed at the entity level. Qualifying structures include:

• Sole proprietorships (Schedule C filers)
• Single-member LLCs taxed as disregarded entities
• Partnerships and multi-member LLCs (Schedule K-1 income)
• S corporations (Schedule K-1 income)
• Certain trusts and estates receiving pass-through income

W-2 employees do not qualify, regardless of income level. C corporations are also excluded — they pay their own entity-level tax and do not pass income to shareholders in a way eligible for the deduction.

Based on our directory of 8,000+ CPAs across the country, the QBI deduction is one of the top five planning items CPAs bring up with self-employed clients and S corp owners. Many business owners either miss it entirely or calculate it incorrectly, leaving significant money on the table. If you want a CPA to run this calculation for your situation, find a CPA near you who specializes in small business tax.

The 2026 Income Thresholds

The QBI deduction has two tiers of complexity based on your taxable income (not gross income — this is after all other deductions, including the standard deduction or itemized deductions):

Below the Threshold: Simple Calculation

For 2026, the lower threshold is approximately $197,300 for single filers and $394,600 for married filing jointly. (These figures are adjusted annually for inflation — confirm exact numbers with your CPA or the IRS for the filing year.) Below these thresholds, the deduction is straightforward: 20% of your qualified business income, subject only to the overall taxable income cap described below.

Above the Threshold: Limitations Apply

Above those thresholds, two additional limitation tests phase in over a $50,000 range for single filers and a $100,000 range for joint filers:

1. The W-2 Wage Limitation: Your deduction cannot exceed the greater of (a) 50% of the W-2 wages your business pays, or (b) 25% of W-2 wages plus 2.5% of the unadjusted basis of qualified depreciable property the business holds.
2. The SSTB Phase-Out: If your business is a Specified Service Trade or Business (see below), the deduction phases out completely once your taxable income exceeds the upper threshold ($247,300 single / $494,600 joint in 2026).

Above the lower threshold but below the upper threshold, both limitations phase in proportionally. A CPA can model exactly where you land and what planning moves shift the outcome.

Specified Service Trades or Businesses (SSTBs)

The most consequential restriction in the QBI rules is the SSTB limitation. If your business falls into one of the following categories, you lose the deduction entirely once taxable income exceeds the upper threshold:

• Health (physicians, dentists, nurses, therapists — but not hospitals or pharmacies)
• Law
• Accounting and actuarial science
• Consulting (broadly defined)
• Financial services and brokerage
• Performing arts and athletics
• Any business where the principal asset is the reputation or skill of its employees or owners

Notably excluded from the SSTB list: engineering, architecture, real estate, and most trades and manufacturing businesses. These are fully eligible for the QBI deduction without the SSTB phase-out, even at high income levels (though the W-2 wage limitation still applies).

For SSTB owners who are near or below the income thresholds, the deduction is still available — the phase-out does not kick in until taxable income exceeds $197,300 (single) or $394,600 (joint). Strategic income management can keep high-earning SSTB owners in or near the eligible range.

How to Calculate the QBI Deduction: Step by Step

The calculation has several layers. Here is the core framework:

1. Determine your qualified business income (QBI) — Net income from your pass-through business, reduced by self-employment tax deduction, self-employed health insurance premiums, and retirement plan contributions attributable to the business. Do not include investment income, capital gains, certain REIT dividends (which get their own QBI treatment), or wages you pay yourself as a guaranteed payment.
2. Calculate the tentative deduction: QBI × 20%
3. Apply the overall income limitation: The deduction cannot exceed 20% of (taxable income − net capital gains and qualified dividends). This prevents high-income taxpayers from using the QBI deduction against investment income taxed at lower rates.
4. Apply the W-2 wage limitation (if above the income threshold): Limit the deduction to the greater of 50% of W-2 wages or 25% of W-2 wages plus 2.5% of qualified property basis.
5. Take the lesser figure from steps 2, 3, and 4 as your actual deduction.

Calculation Example: Below the Threshold

A freelance graphic designer (sole proprietor) with the following 2026 numbers:

• Gross business revenue: $180,000
• Business expenses: $30,000
• Net QBI: $150,000
• Self-employment tax deduction: $10,597
• SEP-IRA contribution: $20,000
• Adjusted QBI: $150,000 − $10,597 − $20,000 = $119,403
• Tentative deduction: $119,403 × 20% = $23,881
• Taxable income (after standard deduction of $15,000): $94,403
• Income cap: $94,403 × 20% = $18,881
• Actual QBI deduction: $18,881 (limited by taxable income cap)

This designer saves approximately $4,144 in federal income tax assuming a 22% marginal rate — a direct reduction in the tax bill, not just taxable income.

Calculation Example: Above the Threshold with W-2 Wages

An S corporation owner (software consultancy, not an SSTB) with these numbers:

• S corp pass-through profit: $350,000
• Reasonable W-2 salary paid to owner: $120,000
• Taxable income (joint filer, after deductions): $420,000
• Tentative deduction: $350,000 × 20% = $70,000
• W-2 wage limitation: 50% × $120,000 = $60,000
• Income cap: $420,000 × 20% = $84,000
• Actual deduction: $60,000 (limited by W-2 wages)

At a 32% marginal rate, this is $19,200 in tax savings. Increasing the W-2 salary slightly — say to $140,000 — raises the W-2 wage limit to $70,000, capturing the full tentative deduction and saving an additional $3,200.

Strategies to Maximize the QBI Deduction

The QBI deduction is not fixed — the mechanics create planning opportunities that a qualified CPA can exploit across several dimensions. See our guide to tax planning strategies for self-employed workers for the broader context these moves fit into.

Adjust W-2 Wages in Your S Corporation

For S corp owners above the income threshold, the W-2 wage limitation is the primary lever. If your deduction is being capped by W-2 wages, increasing your reasonable compensation — within IRS guidelines — raises the wage base and unlocks more deduction. The math: each additional $1 of W-2 wages increases the wage limitation by $0.50. If you are in the 32% bracket, you break even when the additional payroll taxes (15.3% on wages up to the Social Security wage base, then 2.9% above) are offset by the additional QBI deduction. A CPA who understands S corp optimization — like those covered in the LLC vs. S corp vs. C corp comparison — can model the optimal salary precisely.

Reduce Taxable Income to Stay Below Thresholds

For SSTB owners or those near the phase-out range, reducing taxable income below the threshold preserves the full deduction. The most effective tools:

• Retirement plan contributions: A Solo 401(k) allows up to $70,000 in total contributions in 2026 (employee deferrals + employer contributions). A SEP-IRA allows up to 25% of net self-employment income, up to $70,000. Both reduce taxable income dollar for dollar. Read our full breakdown of self-employed retirement accounts for contribution limits and deadlines.
• Health insurance premiums: The self-employed health insurance deduction reduces AGI directly and feeds into lower taxable income.
• Qualified opportunity zone investments, charitable deductions, and timing of income recognition can all shift income across years to optimize threshold positioning.

Aggregate Multiple Businesses

If you own multiple pass-through businesses, IRS regulations allow aggregation — treating multiple businesses as a single entity for QBI purposes. Aggregation can help if one business has strong W-2 wages and another has high income but few employees; combining them raises the wage base relative to the combined income. Aggregation elections must be disclosed on your tax return and maintained consistently once made.

Invest in Qualified Property

For businesses that clear the W-2 wage floor, the alternative W-2 + property test (25% of wages + 2.5% of unadjusted basis of qualified depreciable property) can unlock more deduction. Capital-intensive businesses — manufacturers, contractors, real estate investors — often benefit from this alternative. It also creates an incentive to invest in business equipment or property rather than deferring such purchases.

Consider Entity Structure

The QBI deduction applies to sole proprietors, partnerships, and S corporations — but not C corporations. A business operating as a C corp that converts to an S corp election gains QBI deduction eligibility for its pass-through income. However, entity conversion has tax consequences of its own. This decision should be modeled by a CPA, not made on a heuristic. Our business entity types tax comparison covers the full set of trade-offs.

Common Mistakes That Cost Business Owners Money

Including W-2 Wages in QBI

If you operate an S corporation, the reasonable compensation you pay yourself as a W-2 employee is not QBI. Only the remaining pass-through profit qualifies. Including your W-2 wages in the QBI calculation — a common software error and a common manual error — overstates the deduction and creates an accuracy-related penalty exposure.

Forgetting the Taxable Income Cap

The deduction is limited to 20% of taxable income minus net capital gains. Taxpayers with large capital gains in a given year may find their QBI deduction capped by this provision even if they are below the phase-out thresholds. This is frequently overlooked in simple software calculations.

Misclassifying an SSTB

The SSTB definition is broader than it appears. A business owner who provides consulting services as part of a larger product-based business may find that the consulting revenue is separately analyzed as an SSTB if consulting is significant enough. IRS guidance uses an 80/10 rule: if 80% or more of revenue comes from non-SSTB activities, the business is not an SSTB. Between 10% and 80%, the SSTB portion must be carved out. This requires precise revenue classification.

Not Tracking Unadjusted Basis of Qualified Property

For the W-2 + property alternative limitation, the calculation requires the unadjusted basis (original purchase price, before depreciation) of all qualified depreciable property still in service during the tax year. Many business owners cannot produce this figure because they have not maintained asset schedules. Without it, you cannot claim the alternative limitation — and may leave deduction dollars unclaimed.

Missing the Aggregation Election

The aggregation election must be made on a timely filed return (including extensions). Missing the deadline means foregoing the election for that tax year. Once made, the election generally must be maintained in future years unless there is a significant change in the businesses.

The QBI Deduction and Rental Real Estate

Rental income can qualify for the QBI deduction under specific conditions. The IRS created a safe harbor (Revenue Procedure 2019-38) that treats rental real estate as a trade or business for QBI purposes if the taxpayer maintains separate books, performs 250+ hours of rental services per year, and keeps contemporaneous time records. Outside the safe harbor, whether rental activity constitutes a trade or business is a facts-and-circumstances determination — one where CPA guidance is particularly valuable.

Triple-net leases where the landlord performs minimal services generally do not qualify. Active rental portfolios with multiple properties and active management involvement more commonly qualify.

Verify Your Situation with a CPA

The QBI deduction sits at the intersection of entity structure, income level, business type, and wage decisions — making it one of the few areas where the calculation itself is a planning exercise, not just a compliance task. The strategies above represent real optimization opportunities, but they require accurate numbers and current knowledge of the law.

The deduction was extended beyond its original 2025 sunset date through recent legislation, but tax law continues to evolve. Congress has modified Section 199A before and may do so again. Any planning strategy built around the QBI deduction should be revisited annually with a qualified CPA who tracks legislative developments.

Browse CPAs by city to find a local practitioner with small business tax expertise, or search CPAs near you filtered by specialty. If you work with an accountant rather than a CPA, see our guide on when freelancers specifically benefit from a CPA versus other tax professionals.