The QBI Deduction Explained: How Section 199A Cuts Taxes on Pass-Through Business Income

If you earn income through a small business, partnership, S corporation, or certain real estate investments, you may be eligible for one of the more valuable — and more confusing — deductions created by the 2017 Tax Cuts and Jobs Act: the Qualified Business Income (QBI) deduction under Internal Revenue Code Section 199A. Understanding how it works can meaningfully change what you owe the IRS.

What the Deduction Actually Does

Section 199A allows eligible individuals, trusts, and estates to deduct up to 20% of their qualified business income from a domestic pass-through entity. Pass-through entities — sole proprietorships, partnerships, S corporations, and some trusts — do not pay corporate income tax themselves; instead, profits flow through to the owners' individual tax returns. The QBI deduction was designed to give those business owners a tax benefit roughly analogous to the lower corporate tax rate that C corporations received under the same law.

The deduction also extends to qualified REIT dividends and income from publicly traded partnerships (PTPs), such as many energy infrastructure partnerships, even for investors who hold those securities passively through a brokerage account.

What Counts — and What Doesn't

• Eligible income: net profit from a sole proprietorship (Schedule C), partnership or S corporation pass-through income reported on Schedule K-1, and qualified REIT dividends or PTP income.
• Not eligible: W-2 wages, reasonable compensation paid to an S corporation owner, guaranteed payments to partners for services, capital gains, dividends from C corporations, and interest income not properly allocable to a trade or business.
• The deduction is generally the lesser of 20% of QBI or 20% of taxable income minus net capital gains, so it cannot exceed what your overall tax situation supports.

The Income Thresholds That Change Everything

Below a taxable income threshold set annually by the IRS, most taxpayers can claim the full 20% deduction regardless of their industry or how much they pay employees. Above that threshold, two limitations can kick in. First, for specified service trades or businesses (SSTBs) — a category that includes fields like law, accounting, consulting, health, financial services, and performing arts — the deduction phases out completely once income exceeds the upper end of the phase-in range. Second, for non-SSTB businesses, the deduction above the threshold is capped by a wage-and-capital test: generally 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 business property.

How to Claim It

Most eligible taxpayers below the income threshold use the simplified Form 8995. Those above the threshold, with multiple businesses, or with REIT/PTP income alongside business income typically use the more detailed Form 8995-A, which walks through the SSTB and wage-and-capital calculations line by line. The deduction is taken on the individual Form 1040 and reduces taxable income — it does not reduce self-employment tax or net investment income tax, and it is not an above-the-line deduction for purposes of calculating adjusted gross income.

Practical Takeaways

• Check your entity type: only pass-through structures and certain REIT/PTP income qualify — C corporation dividends do not.
• If you're near the income threshold, timing strategies like retirement plan contributions or deferring income can keep you in the full-deduction range.
• Business owners in service fields should pay close attention to the SSTB rules, since the deduction can disappear entirely above the phase-out ceiling.
• Because dollar thresholds adjust for inflation each year, confirm the current-year figures in the IRS instructions for Form 8995/8995-A before relying on them.
• This provision has a statutory sunset date under current law; monitor IRS guidance and legislative developments for any changes to its availability in future tax years.

This article is for general information and does not constitute tax or investment advice. Taxpayers with pass-through income, especially those near phase-out thresholds or in specified service trades, should consult a qualified tax professional and the IRS's official instructions before filing.