Section 199A Qualified Business Income Tax Deduction

What follows is the super reduced, CliffsNotes version of Section 199A. Prior editions spent two full chapters (Chapters 7 and 8) on aggregation rules, multiple businesses, rental real estate and enough worked examples to cure insomnia. To keep this book from becoming a doorstop, we moved those chapters online, where we can update them when the IRS changes its mind (which it does). See Chapter 7 online at wcginc.com/207 for more information.

“Grandpa, who is Cliff, and why did he take notes?” Ah, we digress!

The Section 199A deduction, also known as the Qualified Business Income (QBI) deduction, arrived with the Tax Cuts and Jobs Act of 2017 and was scheduled to die after the 2025 tax year. The One Big Beautiful Bill Act made it permanent instead, kept it at 20% and sweetened a few rules starting with the 2026 tax year. It is a significant tax break for small business owners, but there are rules and limits, of course.

The deduction is taken on your individual tax return (Form 1040) after adjusted gross income, so it lowers your taxable income but not your AGI. That is a big deal, since AGI (or a modified version of it) drives other limits, such as the $25,000 rental loss allowance under the passive loss rules, Roth IRA eligibility and the medical expense floor, and the Section 199A deduction does nothing to help you there.

It also does not touch self-employment taxes. Earn $100,000 on Schedule C, deduct $20,000 under Section 199A, and you still pay self-employment taxes on the full $100,000.

Who Qualifies for the Section 199A Deduction?

Pass-through businesses and structures include-

• Sole proprietorships (no entity, Schedule C)
• Disregarded entities (single-member LLCs)
• Partnerships and multi-member LLCs
• Any entity taxed as an S corporation
• Rental real estate, but only if the activity rises to the level of a trade or business. Rev. Proc. 2019-38 provides a safe harbor that generally revolves around 250 hours of rental services a year, along with separate books and records and a few other requirements. However, the safe harbor is not required to be used (candidly it stinks as a safe harbor).
• Trusts and estates, plus a separate 20% component for REIT dividends and publicly traded partnership income

C corporations are left out. They got the 21% rate instead.

A Specified Service Trade or Business (SSTB) includes businesses in-

• Health, law, accounting, actuarial science and consulting
• Performing arts and athletics
• Financial services, brokerage services, investing and investment management, trading and dealing in securities or commodities. Good news for realtors and insurance agents: for Section 199A purposes, brokerage services do not include real estate agents and brokers or insurance agents and brokers (Treas. Reg. 1.199A-5(b)(2)(x)).
• Any trade or business where the principal asset is the reputation or skill of its owners or employees

That last one looked like a hammer when the law passed. Then the final regulations defanged it, limiting it to endorsement income, licensing your name or likeness, and appearance fees (Treas. Reg. 1.199A-5(b)(2)(xiv)). So, unless you are getting paid to show up and smile, it probably does not apply to you. We just mixed metaphors too- hammers and fangs.

Interestingly, engineers and architects were purposely left off the list. Every consultant is suddenly going to want to be called an engineer; the software consultant is now a software engineer. Watson Business Engineers has a nice ring to it. Hmm… Sadly, the regulations define consulting by what you actually do, not what is printed on your business card.

Sit on the ledge, sure, but don’t jump off just yet. The SSTB problem only comes up right around the point where your taxable income enters the 32% marginal tax bracket. So, a financial advisor with $150,000 of taxable income still enjoys the full Section 199A deduction. Keep reading!

Section 199A Income Limits

Everything hinges on your household taxable income from all sources before the QBI deduction, not just business income. A handy rule of thumb: the Section 199A threshold tracks the top of the 24% marginal tax bracket, so the fun generally starts as you enter the 32% bracket (as we just mentioned). The two are rounded separately for inflation, so they can differ by a few dollars, but under current law the shortcut works year after year. For the 2026 tax year-

• At or below $201,750 (single) or $403,500 (married filing jointly), you get the full 20% deduction, SSTB or not, with no W-2 wage or property limits.
• Between those thresholds and $276,750 (single) or $553,500 (married filing jointly), the limits phase in. An SSTB gets a shrinking partial deduction, and everyone else starts feeling the W-2 wage and property limits. The One Big Beautiful Bill Act widened this phase-in range from $50,000 to $75,000 (single) and from $100,000 to $150,000 (joint).
• Above $276,750 (single) or $553,500 (married filing jointly), an SSTB gets zero, and everyone else is fully subject to the W-2 wage and property limits. Sorry.

Normally, the deduction is also capped at 20% of your taxable income less net capital gain, whichever way you slice the business income. However, the new minimum deduction below can override that limitation.

New for the 2026 tax year, if you have at least $1,000 of aggregate QBI from qualified trades or businesses in which you materially participate, your minimum Section 199A deduction is $400 (IRC Section 199A(i)). In other words, an applicable taxpayer gets the greater of the normal Section 199A calculation or $400. Both the $1,000 and $400 figures are indexed after 2026.

Calculating the Qualified Business Income Deduction

The basic deduction is 20% of qualified business income. If you have $200,000 of QBI, the deduction is $40,000, which in the 24% bracket puts $9,600 in your pocket.
Above the income limits, the code adds a second test. Here is the exact text of IRC Section 199A(b)(2)-

(2) DETERMINATION OF DEDUCTIBLE AMOUNT FOR EACH TRADE OR BUSINESS. The amount determined under this paragraph with respect to any qualified trade or business is the lesser of-
(A) 20 percent of the taxpayer’s qualified business income with respect to the qualified trade or business, or
(B) the greater of-
(i) 50 percent of the W-2 wages with respect to the qualified trade or business, or
(ii) the sum of 25 percent of the W-2 wages with respect to the qualified trade or business, plus 2.5 percent of the unadjusted basis immediately after acquisition of all qualified property.

Two definitions matter. QBI does not include the reasonable salary an S corporation pays you, guaranteed payments a partnership pays you under IRC Section 707(c), or certain Section 707(a) payments to a partner for services. Swell. And QBI is reduced by deductions attributable to the business, including the deductible half of self-employment tax, self-employed health insurance and retirement contributions (Treas. Reg. 1.199A-3(b)(1)(vi)).

Section 199A Examples

There are some devils in the details, of course. The best way is to show some examples. All income limits below use the 2026 tax year figures.

• Wilma makes $100,000 in net business income from her sole proprietorship and deducts $5,000 for self-employed health insurance, $7,065 for the deductible half of her self-employment taxes and $10,000 for a SEP IRA. Those adjustments reduce her qualified business income (QBI) to $77,935, so her deduction is 20% of $77,935, or $15,587, assuming her taxable income does not cap it lower.
• Barney owns three rentals that rise to the level of a trade or business without needing the safe harbor, with net incomes of $20,000 and $5,000 and one losing $8,000. They net to $17,000, so he deducts 20% of $17,000.
• Barney also has $10,000 of suspended passive losses from 2018 or later that are released this year because he now has net rental income. Those losses reduce his QBI, so his deduction is 20% of $7,000. Suspended losses from before 2018 do not reduce QBI. Good luck tracking that.
• Pebbles earns $100,000 from her pass-through business but reports $80,000 of taxable income because of her itemized deductions. Her deduction is capped at 20% of her $80,000 of taxable income, or $16,000, instead of 20% of her $100,000 of QBI.
• Mr. Slate is single and operates an online retailer through an S corporation that pays $100,000 in W-2 wages and earns $400,000 of QBI. He is the only employee. His taxable income is well above $276,750, so the W-2 wage limit fully applies. His deduction is 50% of the W-2 wages, or $50,000, which is less than 20% of $400,000 (assuming he has little qualified property). In this case, we say Mr. Slate’s QBI deduction is wage limited (a payroll amendment might make sense where distributions paid during the year are reclassified as wages, as long as the corrected W-2s are filed by the deadline).
• If Mr. Slate instead operates as a sole proprietor earning $500,000 with no employees, his W-2 wage limit is $0 and, assuming he has no qualified property, so is his deduction. If he elects S Corp status and pays himself $200,000 in wages, leaving $300,000 of QBI, his deduction is the lesser of 20% of $300,000 or 50% of $200,000, so $60,000. That ignores the payroll tax cost of the salary, which is the optimization problem below. In this case, an S Corp election is required so he can pay a wage to himself.
• If Mr. Slate instead operates an SSTB, his deduction completely disappears once his taxable income exceeds $276,750 (single) or $553,500 (married filing jointly) for the 2026 tax year. This is the SSTB “gotcha.” Between $403,500 and $553,500 on a joint tax return, he gets a sliding scale. Silly rabbit, tax reform doesn’t mean tax simplification.
• Fred is single and operates an accounting practice as an S Corp, paying himself $50,000 in W-2 wages and earning $100,000 of QBI. He is clearly an SSTB, but with total income of $150,000 he is under the $201,750 threshold, so he takes the full 20% of $100,000, or $20,000. We are not entertaining the reasonable salary question here.
• Betty becomes a slumlord with $500,000 of net rental income from a trade or business and no W-2 employees. Her properties cost $1,000,000, not counting land. The math goes like this-20% of $500,000 is $100,000 (straight calculation)
  50% of $0 in W-2 wages is $0 (wage calculation)
  2.5% of $1,000,000 is $25,000 (property calculation)

  Her deduction is the lesser of $100,000 or the greater of $0 and $25,000, so $25,000.

Section 199A Takeaways

• Taxable income from all sources is the trigger. One dollar over the threshold starts the SSTB phase-out and the W-2 wage and property limits.
• W-2 wages include wages paid to all employees, not just the owners. If a worker properly belongs on payroll, those wages can help the Section 199A calculation. Worker classification follows the facts, however, so don’t turn a legitimate independent contractor into an employee merely to juice the deduction. Or at least keep it to yourself.
• S corporations remain a critical tax saving tool for two reasons. First, the self-employment tax savings remain intact for everyone, including SSTBs. Second, above the income limits a business owner might need W-2 wages to support the deduction, and an LLC cannot pay its owner W-2 wages unless it is taxed as an S Corp (sure, you could elect C Corp status for your LLC, but C Corp income does not qualify for Section 199A, which defeats the purpose here).

Section 199A Pass-Through Optimization

As you can see, some optimization is necessary to get the most from the Section 199A deduction. With respect to S Corps, we want lower shareholder salaries to minimize payroll taxes. On the other hand, above the income limits, we want higher salaries so the W-2 wage limit does not choke the deduction.

The trade-off is not as obvious as 15.3% payroll taxes versus a 20% deduction, since the 20% deduction must be multiplied by your marginal tax rate to find the real tax benefit. Even at a 37% marginal rate, the additional payroll taxes might exceed the extra Section 199A benefit.

Spoiler Alert: For a non-SSTB above the income limits where the 50% W-2 wage limit binds, the salary that maximizes the Section 199A deduction is about 27.9% of net business income before salary, or about $28,000 on $100,000. That is the 199A answer, not the whole answer, since payroll taxes and the reasonable salary rules get a vote. We cover the full optimization in Chapter 7 which has been moved to online only at wcginc.com/207.