Qualified Business Income Deduction

The Qualified Business Income (QBI) Deduction, enacted in the Tax Cuts and Jobs Act of 2017, allows individual taxpayers to deduct up to 20% of their pass-through business income. However, the deduction phases out for high earners and is progressively limited by the W-2 wages the business has paid—a quirk that ties individual tax relief to employee payroll.

The headline: 20% deduction for business owners

The simplest version of the QBI deduction is appealing: if you own a pass-through business (an S corp, partnership, LLC, or sole proprietorship), you can deduct 20% of your net business income without itemising and without reducing your business expense basis. A sole proprietor with $100,000 in net profit can deduct $20,000, reducing taxable income to $80,000.

This is a substantial benefit, equivalent to a 20% discount on pass-through income. The deduction applies below the line—it is not an above-the-line adjustment—and does not reduce self-employment tax or the income used to calculate other limitations, but it does reduce the income subject to the marginal tax rate.

Phase-out for high earners

The deduction is not available to high-income taxpayers without limitation. For individuals with taxable income exceeding a threshold ($182,100 for single filers in 2024; $364,200 for married filing jointly; adjusted annually for inflation), the deduction is phase-out, and different rules apply.

Below the threshold, most taxpayers can claim the full 20% deduction (subject to other limits). Above the threshold, the deduction is restricted by the W-2 wage limitation and a limitation tied to the unadjusted basis of qualified property. This two-tier system means that a software developer earning $500,000 in S corp income faces a stricter deduction than one earning $150,000.

The W-2 wage limit and qualified property

Once a taxpayer exceeds the threshold, the deduction is limited to the greater of:

1. 20% of the taxpayer’s share of QBI, or
2. The lesser of (a) 20% of QBI, or (b) the sum of (i) 50% of W-2 wages paid by the business in the tax year, plus (ii) 2.5% of the unadjusted basis of qualified property.

This formulation is dense, but the intent is clear: high-income business owners are rewarded for paying employees and investing in tangible property. A business paying substantial W-2 wages gets a larger deduction. A business with no employees and minimal fixed assets gets a much smaller deduction at high income levels.

For example, suppose a high-income S corp owner’s share of QBI is $300,000. The 20% base deduction would be $60,000. But if the business paid only $50,000 in W-2 wages and had negligible property, the W-2 wage limitation becomes 50% × $50,000 + 2.5% × $0 = $25,000. The deduction is capped at $25,000, far less than the $60,000 base.

This rule discourages high-income pass-through owners from using aggressive tax strategies (such as taking all income as distributions while avoiding W-2 wages). It also advantages capital-intensive and labor-intensive businesses over asset-light service businesses.

Calculating QBI

Qualified business income is generally the net profit (or loss) from the pass-through entity, computed in the same way as it would be for self-employment tax purposes. Income includes gross profit minus deductions for cost of goods sold, wages, rent, utilities, and other ordinary and necessary business expenses.

Certain types of income are excluded from QBI: capital gains and losses, dividend income, interest income not derived from the business, and income from passive activities. A business owner with $50,000 in W-2 wages, $70,000 in business profits, and $20,000 in capital gains from selling business property calculates QBI on the $70,000 profit, not the $90,000 total.

Interaction with self-employment tax

The QBI deduction does not reduce income for SE tax purposes. A sole proprietor with $100,000 in net business income pays SE tax on $100,000, even though the QBI deduction may reduce taxable income to $80,000. This is a key distinction: the self-employment tax deduction (50% of SE tax paid) and the QBI deduction (20% of business income) operate on different income bases and serve different purposes.

Specified service businesses (SSBs)

Certain high-income professionals in specified service businesses—such as health, law, accounting, consulting, and athletics—face additional restrictions. Even below the phase-out threshold, an SSB owner’s QBI deduction may be further limited. The rules reflect Congressional concern that service businesses could shift income to lower-bracket family members or use other tax planning strategies if the deduction were unrestricted.

Coordination with other deductions and credits

The QBI deduction is computed in the tax return’s final stages, after all other deductions and credits have been determined. It does not reduce adjusted gross income and therefore does not affect AGI-based limitations such as IRA contribution limits or passive loss deductions. A taxpayer with $200,000 in W-2 income and $100,000 in QBI has an AGI of $300,000, not $280,000 (even if the full QBI deduction of $20,000 applies), which matters for other tax calculations.

Temporary status and future uncertainty

The QBI deduction was enacted as part of the 2017 tax cuts and was originally scheduled to expire after 2025. As of early 2026, Congress has extended or made permanent various provisions, but the QBI deduction’s permanent status remains subject to legislative action. Taxpayers and advisors should monitor future tax law changes, as a sunset or phase-out of the deduction would significantly increase taxes on pass-through business owners.

See also