QBI Deduction Explained: How Pass-Through Businesses Claim 20%

The QBI deduction, established under Section 199A of the Internal Revenue Code, allows eligible owners of pass-through businesses to deduct up to 20% of their qualified business income from federal taxable income. It applies to sole proprietors, partnerships, S corporations, and certain trusts and estates. The One Big Beautiful Bill Act (OBBBA), signed July 4, 2025, made the deduction permanent, removing the prior December 31, 2025 sunset. For 2026, the full deduction is available to taxpayers below the income thresholds; above those thresholds, wage and property limitations phase in, and owners of specified service trades or businesses (SSTBs) face additional restrictions.

What Is the QBI Deduction and Who Qualifies?

The qualified business income deduction lets pass-through business owners reduce their taxable income by up to 20% of QBI without itemizing. Unlike a tax credit, it reduces the income subject to tax rather than the tax owed directly, but the effective rate reduction can be substantial for profitable operations. The IRS QBI deduction overview sets out the core eligibility rules.

To qualify at the basic level, a taxpayer must:

• Operate a qualified trade or business (a regular, continuous activity conducted for profit)
• Earn income that flows through to their individual return (sole proprietor, partnership, S corporation, REIT dividends, or qualified publicly traded partnership income)
• Have positive QBI from that activity

Wage income (W-2 pay) from a business does not count as QBI even if you are also an owner. C corporation income does not qualify at all since it is taxed at the entity level.

What Counts as Qualified Business Income

QBI is the net amount of qualified items of income, gain, deduction, and loss from a domestic qualified trade or business. This means ordinary business profit, not capital gains or losses, dividends, interest income (unless allocable to the business), or certain other investment-type income. If a business shows a net loss for the year, that negative QBI carries forward to offset future years’ QBI.

2026 Income Thresholds and How They Work

For 2026, per IRS Rev. Proc. 2025-32, the baseline income thresholds are:

• $201,750 for single filers, heads of household, and qualifying surviving spouses
• $403,500 for married filing jointly

Taxpayers whose taxable income falls at or below these amounts can generally claim the full 20% QBI deduction with no further calculation. The deduction is simply 20% of QBI, subject to an overall cap of 20% of (taxable income minus net capital gains).

Above the thresholds, two additional rules phase in: the W-2 wage and qualified property limitation, and, for service businesses, the SSTB phase-out. These rules apply across a phase-in range that OBBBA expanded for 2026: $75,000 above the threshold for single and other filers, and $150,000 above the threshold for joint filers.

The W-2 Wage and Property Limitation

Once taxable income exceeds the threshold, the QBI deduction is capped at the greater of:

1. 50% of W-2 wages paid by the business, or
2. 25% of W-2 wages plus 2.5% of the unadjusted basis immediately after acquisition (UBIA) of all qualified property

Qualified property means tangible, depreciable property held by the business and still in its depreciable period at year end. This provision often matters for capital-intensive businesses with significant equipment or real estate. A manufacturing company with a large property base but modest wage costs may find the 25% + 2.5% UBIA test produces a larger ceiling than the pure wage test.

For businesses in the phase-in range (between the threshold and the threshold plus the range), the limitation applies only partially and is blended based on how far income falls into the range.

The New $400 Minimum Deduction

OBBBA added a floor that did not exist before. Starting in 2026, any taxpayer with at least $1,000 of QBI from an actively conducted qualified trade or business may claim a minimum QBI deduction of $400, even if the W-2 wage test would otherwise produce a smaller amount. Both the $1,000 and $400 amounts are inflation-indexed for years after 2026. This change primarily benefits small businesses that pay little or no W-2 wages.

How SSTBs Are Treated Under Section 199A

A specified service trade or business (SSTB) is treated differently because Congress intended the deduction to reward traditional production businesses more than high-income professional service firms.

IRS regulations under Section 199A (Treas. Reg. §1.199A-5) define an SSTB as a trade or business involving the performance of services in:

• Health (physicians, dentists, veterinarians, therapists)
• Law
• Accounting
• Actuarial science
• Performing arts
• Consulting
• Athletics
• Financial services and investment management
• Any business where the principal asset is the reputation or skill of one or more owners or employees

Engineering and architecture are explicitly excluded from the SSTB definition, which is why those fields receive the full deduction treatment even at higher income levels.

How the SSTB Phase-Out Works

For SSTB owners, the deduction phases out entirely once taxable income exceeds the threshold by more than the phase-in range. For 2026:

• Single filers: SSTB deduction phases out completely above $276,750 (i.e., $201,750 + $75,000)
• Joint filers: SSTB deduction phases out completely above $553,500 (i.e., $403,500 + $150,000)

Inside the phase-in range, the deduction is partially available and calculated on a sliding scale. Below the base threshold, an SSTB owner qualifies for the full 20% deduction just like any other business owner.

Practically speaking, a single physician with $220,000 in taxable income sits inside the phase-in range and retains a partial QBI deduction. One with $300,000 in taxable income receives nothing from the SSTB income because the phase-out is complete. This creates real planning stakes around retirement contributions, entity structure, and timing of income.

Calculating the Deduction: A Practical Walkthrough

Consider three simplified 2026 examples.

Example 1: Below threshold, simple case. A single-member LLC (taxed as a sole proprietor) reports $150,000 in net business income. Taxable income is $130,000 after the standard deduction. This is below the $201,750 threshold, so the deduction is straightforwardly 20% x $130,000 QBI = $26,000, subject to the 20% of taxable income overall cap.

Example 2: Above threshold, non-SSTB. An S corporation owner-operator in manufacturing has $500,000 in taxable income and $400,000 in QBI. The W-2 wages paid by the S corporation total $200,000; UBIA of equipment is $600,000. Wage test: 50% x $200,000 = $100,000. Alternative test: 25% x $200,000 + 2.5% x $600,000 = $50,000 + $15,000 = $65,000. The binding limit is $100,000 (the larger result). The raw 20% deduction would be $80,000, which is below $100,000, so the wage cap is not the binding constraint here. The deduction is $80,000.

Example 3: SSTB owner near phase-out. A consultant filing jointly has $500,000 in taxable income. The base threshold is $403,500 and the complete phase-out ceiling is $553,500. The taxpayer is 65% of the way through the phase-in range, so 65% of the SSTB deduction is phased out. Only 35% of the otherwise available QBI deduction remains.

These examples simplify real situations. Multiple entities, losses, and aggregation elections add complexity.

Aggregation of Multiple Businesses

Owners of multiple qualified trades or businesses may elect to aggregate them for the wage and property limitation test, provided the businesses meet common ownership and integration requirements. Aggregation can increase the deduction ceiling when one entity has strong W-2 wages and another has most of the QBI. The election must be disclosed on the tax return and applied consistently in later years.

Planning Opportunities to Maximize the QBI Deduction

The deduction creates specific planning leverage points:

Entity structure. An S corporation owner can adjust the split between W-2 salary and pass-through distributions. Higher salary increases the wage base used in the limitation test, which can raise the QBI deduction ceiling for high-income owners. However, raising salary also increases payroll taxes, so the tradeoff must be modeled carefully.

Retirement plan contributions. Pre-tax contributions to a SEP-IRA, Solo 401(k), or defined benefit plan reduce taxable income. For taxpayers near the SSTB phase-out threshold, reducing taxable income below the threshold with deductible retirement contributions can preserve or restore the QBI deduction. The dollar impact on total tax can be magnified because the contribution reduces both ordinary income tax and saves the QBI deduction.

Qualified property investment. For capital-intensive businesses above the wage threshold, investing in depreciable equipment increases the UBIA component of the alternative wage test, raising the deduction ceiling.

Income timing. Deferring income or accelerating deductions in a high-income year can shift taxable income below a threshold. The stakes are higher for SSTB owners since the deduction disappears entirely above the phase-out ceiling.

Business separation or combination. A mixed business that earns both SSTB and non-SSTB income is tested under the de minimis rule in Treas. Reg. Section 1.199A-5(c)(1). A trade or business is not treated as an SSTB if its SSTB activities generate less than 10% of gross receipts, or less than 5% if gross receipts exceed $25 million. Keeping SSTB and non-SSTB lines in separate entities with their own books can preserve the deduction on the non-SSTB side, while aggregation elections allow combining entities that might individually fail the wage test.

A Modus tax advisor can model these scenarios with your actual projections before year end, when most of these elections and decisions still have time to matter.

REIT Dividends and PTP Income

The QBI deduction also covers 20% of qualified REIT dividends and qualified publicly traded partnership (PTP) income, regardless of taxable income level and without any W-2 wage or property limitation. These components are not subject to the SSTB rules either. Investors who own REITs in taxable accounts, or who hold interests in qualified PTPs, can take this portion of the deduction even if they have no active business income.

Interaction with Other Tax Provisions

The QBI deduction is taken on the individual return after calculating adjusted gross income (AGI). It reduces taxable income but does not affect AGI-based phase-outs, so it does not impair eligibility for IRA contributions, education credits, or other AGI-sensitive items.

The deduction is allowed for alternative minimum tax (AMT) purposes as well. Under Section 199A(f)(2), qualified business income is determined without regard to any AMT adjustments, so the same deduction reduces both regular taxable income and alternative minimum taxable income. Taxpayers subject to AMT do not lose the benefit.

Net investment income tax (NIIT) at 3.8% applies to passive business income in some cases and is calculated separately from the income tax rate. The QBI deduction reduces ordinary income tax but does not reduce NIIT exposure for passive owners.

For businesses weighing structure choices, Modus advisory services can analyze the full tax cost of different entity elections alongside QBI deduction access, NIIT, and self-employment tax implications.

Related reading: S-Corp vs. C-Corp: Which Entity Saves Owners More?

Frequently Asked Questions

What is the QBI deduction and who qualifies?

The QBI deduction (Section 199A) allows owners of pass-through businesses, including sole proprietors, partnerships, and S corporations, to deduct up to 20% of qualified business income from their taxable income. Qualifying taxpayers must operate an active trade or business and have positive QBI. The deduction is permanent as of the OBBBA signed in July 2025. High-income owners face additional wage/property limitations, and owners of specified service trades or businesses (SSTBs) face a phase-out above the income thresholds.

Does my S corporation qualify for the QBI deduction?

Yes, S corporations are pass-through entities and their owners can take the QBI deduction on their individual returns based on their share of the corporation’s QBI. Owners who also pay themselves a reasonable W-2 salary from the S corporation benefit from having that wage amount count toward the W-2 wage limitation ceiling, which matters at higher income levels.

Can SSTB owners get any QBI deduction in 2026?

Yes, if their taxable income is at or below the threshold ($201,750 single / $403,500 joint), SSTB owners qualify for the full 20% deduction just like any other business. The deduction phases out gradually across the next $75,000 (single) or $150,000 (joint) of taxable income, and disappears completely above those upper limits. Strategic retirement contributions can sometimes push taxable income below the phase-out range.

What is the W-2 wage limitation and when does it apply?

The W-2 wage limitation caps the QBI deduction for taxpayers above the income threshold. It limits the deduction to the greater of: 50% of W-2 wages paid by the business, or 25% of W-2 wages plus 2.5% of the unadjusted basis of qualified depreciable property. Taxpayers below the threshold ignore this test entirely.

Does the QBI deduction apply to rental income?

It can. Rental activity qualifies if it rises to the level of a trade or business under Section 162 standards, or if the taxpayer uses the IRS safe harbor for rental real estate finalized in Rev. Proc. 2019-38, which generally requires 250 or more hours of rental services per year plus separate books and contemporaneous records. Triple net leases and property used as a residence are excluded from the safe harbor. Passive investors who merely hold rental property without active involvement generally cannot claim the deduction. REIT dividends, however, always qualify for the 20% deduction regardless of activity level.

How does the new $400 minimum deduction work?

OBBBA added a minimum QBI deduction starting in 2026. If a taxpayer has at least $1,000 of QBI from an active qualified trade or business and materially participates in it, they can claim at least $400 as a QBI deduction even if the standard calculation (after W-2 wage limits) would produce less. Both the $1,000 threshold and the $400 minimum are inflation-indexed for future years.