QBI Deduction 2026 Complete Guide: Section 199A Permanent Extension, $201,750 Thresholds, and New $400 Minimum Under OBBBA

By Marcus Rodriguez, CPA | Published: July 10, 2026 | Updated: July 20, 2026

Key Topics: Section 199A Permanent Extension OBBBA, QBI Deduction 2026 $201,750 Threshold, $75K Phase-in Range Single, New $400 Minimum Deduction §199A(i), SSTB Phaseout Architect Engineer Excluded, W-2 Wages UBIA Limitation, Form 8995 vs 8995-A, QBI Aggregation Election 2026, Pass-Through Business Tax Strategy

If you own a pass-through business—sole proprietorship, LLC taxed as a disregarded entity, partnership, or S-corporation—the Section 199A Qualified Business Income (QBI) deduction has probably been your single most valuable tax break since 2018. And here's the biggest news in years for QBI: the One Big Beautiful Bill Act (OBBBA §70105, P.L. 119-21, signed July 4, 2025) made the QBI deduction PERMANENT. The old December 31, 2025 sunset date is gone—gone for good. But permanence isn't the only change. OBBBA also dramatically expanded the QBI phase-in ranges from $50,000/$100,000 to $75,000/$150,000 above threshold, and added an entirely new §199A(i) that creates a $400 minimum QBI deduction for active qualified trades or businesses with at least $1,000 of QBI.

For 2026, the IRS inflation-adjusted thresholds under Rev. Proc. 2025-32 are: $201,750 for single filers and heads of household, $403,500 for married filing jointly, and $201,775 for married filing separately. The deduction itself still follows the core framework: the greater of (A) 20% of qualified business income plus 20% of qualified REIT dividends and publicly traded partnership (PTP) income, or (B) that same combined amount capped at 20% of (taxable income minus net capital gain). But the mechanics of when the W-2 wages and UBIA limitations kick in, and who gets phased out as an SSTB, have shifted meaningfully.

In the 14 years I've been preparing pass-through returns, I don't think I've had a single client where QBI wasn't the most complex deduction on the return—and simultaneously the most valuable. I had a married couple who are both physical therapists last year — they thought because they're in health they could never claim QBI. Turns out their combined $350K MFJ income was still BELOW the old threshold, so they got the full 20% on both their practices and saved over $12,000 on their return. That's the kind of money that pays for a child's braces, funds a Roth IRA for both spouses, or just lets you sleep better at night. The purpose of this guide is to make sure you don't leave that kind of money on the table. I'll walk you through every OBBBA change, every threshold, every limitation, every filing form, and every planning strategy you need for 2026.

Three Big OBBBA Changes to QBI in 2026

Before we dive into the 2026 numbers and calculations, let's anchor ourselves on the three material changes that OBBBA §70105 made to IRC §199A. These are not tweaks at the margins—they fundamentally change how millions of pass-through businesses interact with the deduction.

Change 1: The QBI Deduction Is Permanent (No More December 31, 2025 Sunset)

The original TCJA Section 199A was enacted as a temporary provision effective for tax years 2018 through 2025. Every year since 2018, I've had clients asking me, "Should I structure this transaction assuming QBI will be extended?" My standard answer was, "Plan for QBI to expire, hope it gets renewed." That answer is now obsolete. OBBBA §70105(a) struck the sunset language in §199A(i) (the old sunset paragraph—now repurposed for the minimum deduction) and replaced it with permanent effectiveness. For tax planning purposes, this is massive. You can now make long-term entity choice decisions—S-corp vs. sole prop, partnership structure, aggregation elections—assuming the QBI deduction is here to stay. No more year-to-year uncertainty. For multi-year purchase price allocations in business acquisitions, for compensation structuring in S-corps, for retirement plan contributions that affect your taxable income relative to the threshold, permanence changes everything.

Change 2: Expanded Phase-In Ranges — Old $50K/$100K → New $75K/$150K

This is the change that will move the needle for the largest number of taxpayers. Under pre-OBBBA law, the QBI "phase-in range"—the band of income above the threshold where the W-2/UBIA limitation gradually kicks in for non-SSTBs, and where SSTB eligibility gradually phases out to zero—was $50,000 wide for single filers and heads of household, and $100,000 wide for married filing jointly. OBBBA §70105(b) increased those ranges by 50%: $75,000 for single/HOH and $150,000 for MFJ. The MFS range is half of MFJ, so $75,000 as well (consistent with how the old $50K single mapped to $100K MFJ). What does this mean in practice? It means the W-2/UBIA limitation phases in 33% more slowly, and SSTBs have 33% more room before they're completely phased out. A single-filer management consultant (SSTB) with $230,000 of taxable income would have been 56% through the old phase-in range (and thus lost 56% of their QBI deduction). Under the new wider range, they're only 38% phased in—meaning they keep 62% of their deduction instead of 44%. That's thousands of dollars in real savings for a single tax return, just from a wider phase-in band.

Change 3: New §199A(i) — The $400 Minimum Deduction for Active QTBs with ≥$1,000 QBI

This is the brand-new provision that nobody saw coming, and it's a gift to America's smallest businesses. OBBBA §70105(c) added a new IRC §199A(i) that creates a minimum QBI deduction rule. Here's how it works: If you have one or more "active qualified trades or businesses" (QTBs), and the total QBI from all active QTBs combined is at least $1,000 for the tax year, then your QBI deduction is the GREATER of (A) the QBI deduction you would normally calculate under the regular rules, OR (B) $400. This $400 minimum is inflation-adjusted for tax years after 2026, per §199A(i)(3). This is a game-changer for microbusinesses whose regular QBI calculation would otherwise produce a tiny or zero deduction—think about the Etsy seller with $1,200 of net QBI whose 20% deduction is only $240 under normal rules. Under §199A(i), that deduction bumps to $400 instead. For a part-time dog walker who nets $1,500 on Schedule C, the 20% deduction is $300 normally—but now they get $400. The key restriction: this minimum only applies to active QTBs. Passive activities (within the meaning of §469) and qualified REIT dividends/PTP income don't count toward the $1,000 threshold and don't generate the minimum. If you have a mix of active and passive, only the active QTB QBI counts toward the $1,000 test.

Source: IRC §199A as amended by OBBBA §70105 (P.L. 119-21), signed July 4, 2025

2026 QBI Thresholds and the Three-Income Regime

The QBI deduction operates in three distinct regimes depending on where your taxable income (before the QBI deduction itself) falls relative to the inflation-adjusted thresholds. This "three-regime" framework is the backbone of the entire §199A calculation, and understanding which regime you're in before you do anything else will save you hours of confusion.

The 2026 threshold amounts are published in Rev. Proc. 2025-32, which the IRS released in Internal Revenue Bulletin 2025-45. The table below shows the full picture:

Filing Status	Threshold (Phase-In Begins)	Phase-In End (Fully Phased In)	Range Width
Single	$201,750	$276,750	$75,000
Head of Household (HOH)	$201,750	$276,750	$75,000
Married Filing Jointly (MFJ)	$403,500	$553,500	$150,000
Married Filing Separately (MFS)	$201,775	$276,775	$75,000

Source: Rev. Proc. 2025-32, Internal Revenue Bulletin 2025-45

Regime 1: BELOW the Threshold (Taxable Income ≤ $201,750 Single/HOH, ≤ $403,500 MFJ)

This is the simplest regime and the one most taxpayers fall into. If your taxable income (determined without regard to the QBI deduction itself, and including all your wages, capital gains, dividends, interest, retirement distributions, etc.) is at or below the threshold for your filing status, the W-2 wages and UBIA limitation does NOT apply. At all. Zero. You simply calculate 20% of your QBI from each qualified trade or business, add 20% of your qualified REIT dividends and PTP income, and then cap the combined total at 20% of (taxable income minus net capital gain). That's it. No schedules, no worksheets, no complex apportionment. This is also the regime where SSTB status is COMPLETELY IRRELEVANT. I'll repeat that because I can't tell you how many times I've corrected a client on this: if you're below the threshold, SSTB status does NOT matter. A plastic surgeon making $300,000 MFJ with a solo S-corp? Below the old 2025 threshold and still below the 2026 $403,500 threshold. Full 20% QBI deduction, no SSTB issue whatsoever. That married couple of physical therapists I mentioned earlier? This is exactly their situation. Don't let the SSTB label scare you until you know where your income lands.

Regime 2: WITHIN the Phase-In Range ($201,751–$276,750 Single/HOH, $403,501–$553,500 MFJ)

Here's where it gets interesting—and where the new wider range helps. If you're within the phase-in band, two things happen simultaneously, each pro-rated by how far through the range you are. First, for non-SSTBs: the W-2 wages and UBIA limitation gradually phases in. Second, for SSTBs: the allowable QBI gradually phases out, reaching zero at the top of the range. The proration ratio is: (Taxable Income − Threshold) ÷ Range Width. So if you're single with $239,250 of taxable income, that's $37,500 into the $75,000 range—exactly 50% phased in. For non-SSTBs, 50% of the excess deduction (the difference between the tentative 20%-of-QBI amount and the W-2/UBIA limitation amount) is disallowed. For SSTBs, 50% of your QBI from SSTBs is excluded from the deduction calculation entirely. The wider $75K/$150K ranges mean this proration happens at a gentler slope—each additional dollar of taxable income causes a smaller step-down in QBI benefit than it did under the old narrower ranges.

Regime 3: ABOVE the Phase-In Range (≥ $276,750 Single/HOH, ≥ $553,500 MFJ)

At and above the phase-in end, everything crystallizes. For non-SSTB qualified trades or businesses, the W-2 wages and UBIA limitation is fully applied—your deduction from each QTB is the lesser of (A) 20% of QBI, or (B) the greater of (i) 50% of W-2 wages with respect to the QTB, or (ii) 25% of W-2 wages plus 2.5% of the unadjusted basis immediately after acquisition (UBIA) of all qualified property held and used in the QTB. For SSTBs, your deduction is ZERO. Zip. Nada. If you're a single-filer dermatologist with $300,000 of taxable income in 2026, you're $23,250 above the $276,750 phase-in end—you get no QBI deduction at all from your SSTB practice. But if you're a single-filer restaurant owner (non-SSTB) with the same $300,000 taxable income, you still get a QBI deduction—it's just limited by the full W-2/UBIA formula.

The W-2 Wages and UBIA Limitation (Greater of 50% W-2 OR 25% W-2 + 2.5% UBIA)

The W-2 wages and UBIA limitation is the guardrail Congress built into §199A to prevent pure passive investors (think: a solo consulting practice with no employees and no fixed assets that generates $1 million a year from a single personal-services contract) from claiming the full 20% deduction. It only fully applies in Regime 3 (above the phase-in range) and partially applies in Regime 2 (within the range).

The limitation per qualified trade or business is the GREATER of two tests: Test 1 is 50% of the W-2 wages properly allocable to the QTB. Test 2 is 25% of W-2 wages allocable to the QTB PLUS 2.5% of the unadjusted basis immediately after acquisition (UBIA) of all qualified property (tangible, depreciable property used in the QTB, still within its recovery period). You use whichever test produces the higher number—that's the maximum QBI deduction you can take from that business, after the 20%-of-QBI cap.

Let's work through a concrete example to see how this operates in Regime 2 (within the phase-in range), which is where the expanded $75K/$150K ranges change outcomes the most.

Worked Example: Restaurant Owner $300K QBI Non-SSTB, MFJ Taxable $500K

Meet Jennifer and Carlos Ramirez. They own a family-style Italian restaurant in Newark, NJ, operated as an LLC taxed as a partnership. The restaurant generates $300,000 of qualified business income in 2026. They pay W-2 wages of $180,000 to their kitchen staff, servers, and a general manager. The UBIA of their qualified property—commercial kitchen equipment, dining room furniture, POS system, leasehold improvements—is $600,000. Their joint taxable income before the QBI deduction is $500,000 (no capital gains this year).

Step 1: Determine the regime. MFJ threshold is $403,500; phase-in end is $553,500. $500,000 is within the range. Regime 2 applies.

Step 2: Calculate the proration ratio. Excess over threshold = $500,000 − $403,500 = $96,500. Range width = $150,000. Ratio = $96,500 ÷ $150,000 = 64.33% (0.6433).

Step 3: Tentative QBI deduction without limitation = 20% × $300,000 = $60,000.

Step 4: W-2/UBIA limitation amount = Greater of (50% × $180,000 = $90,000) OR (25% × $180,000 + 2.5% × $600,000 = $45,000 + $15,000 = $60,000). So the limitation is $90,000. Since $60,000 (the tentative 20% of QBI) is already LESS than $90,000 (the limitation), the W-2/UBIA limitation—even fully applied—wouldn't reduce their deduction at all. Wait, that means Regime 2 doesn't cost them anything? Exactly. In this case, the business has enough W-2 wages that even at full limitation there's no haircut. Their only potential cap is the overall taxable income cap: 20% × ($500,000 − $0 net cap gain) = $100,000. Since $60,000 < $100,000, the overall cap doesn't apply either. The Ramirezes' QBI deduction is the full $60,000—plus whatever the new $400 minimum gives them, though the regular calculation already exceeds $400, so no additional minimum benefit. That's $60,000 off their taxable income. In the 24% bracket, that's $14,400 of federal income tax saved.

Now let me show you what would have happened under the old, narrower phase-in range. Under pre-OBBBA law with the same $300K QBI and $500K taxable MFJ, the phase-in range would have been $85,000 wide (assuming a ~$415K old threshold). The proration ratio would have been roughly 94% instead of 64%—but again, since the limitation doesn't actually constrain this business, the outcome is the same. The benefit of the wider range is most dramatic for businesses where the W-2/UBIA limitation WOULD bite, or for SSTBs. Let me show you an SSTB example to see the difference. Take a single-filer financial planner (clear SSTB) with $230,000 taxable income and $180,000 QBI. Under old law with a ~$185K threshold and $50K range: ($230K − $185K) ÷ $50K = 90% phased out. QBI deduction: only 10% × 20% × $180K = $3,600. Under new 2026 law: ($230K − $201,750) ÷ $75K = 37.67% phased out. So 62.33% remains: 62.33% × 20% × $180K = $22,439. That's an $18,839 increase in the deduction, translating to roughly $4,500 in federal income tax saved for the same income, same business, same year—purely from the wider phase-in range. This is the OBBBA change you can see in your bottom line.

SSTBs: Specified Service Trades or Businesses — Who Is In, Who Is Out

The SSTB classification is the single most emotional topic in QBI planning. My email inbox is flooded every tax season with questions like "I'm a software developer—am I consulting? Am I SSTB?" or "I do interior design—does that count?" Let's get this straight with absolute clarity from the statute and the regulations.

IRC §199A(d)(2) defines an SSTB as any trade or business involving the performance of services in the fields of: health, law, accounting, actuarial science, performing arts, consulting, athletics, financial services, brokerage services, or any trade or business where the principal asset is the reputation or skill of one or more employees or owners. Treasury Regulation §1.199A-5(b) expands on each category and provides examples. The list of categories IN the SSTB definition includes, but is not limited to:

• Health: Physicians, surgeons, dentists, veterinarians, physical therapists, occupational therapists, pharmacists, nurses, nurse practitioners, physician assistants, and other healthcare professionals who provide medical services directly to patients. Hospital operators are generally NOT SSTB—only the professional service providers themselves.
• Law: Lawyers, paralegals performing legal services, arbitrators, mediators, legal document preparers performing legal services.
• Accounting: CPAs, enrolled agents, tax preparers, bookkeepers performing attest services, forensic accountants.
• Actuarial science: Actuaries performing actuarial services.
• Performing arts: Actors, singers, musicians, dancers, performers, directors, choreographers. Theater and venue operators are NOT in this category.
• Consulting: Providing advice and counsel to clients to achieve goals. This is the most litigated category. Software development that consists of providing advice on system architecture IS consulting; software development where you write code to a client's specifications but don't provide strategic advice MAY not be. The facts and circumstances matter enormously.
• Athletics: Professional athletes, coaches, team trainers, sports agents.
• Financial services: Financial advisors, wealth managers, investment bankers, financial planners, bankers performing financial services.
• Brokerage services: Stockbrokers, real estate brokers and agents, insurance agents receiving commissions (though some insurance agency structures have been successfully argued as non-SSTB).
• Investment management / trading / partnership interest allocation: Hedge fund managers, private equity managers, commodity trading advisors.
• The "reputation or skill" catchall: Endorsements, licensing of image/likeness/name, appearance fees. This is narrow despite its broad-sounding name—the IRS and courts have consistently interpreted it narrowly to the three specific types of income listed in the regulation, not to every business that relies on owner skill.

The Two Critical EXCLUSIONS: Engineering and Architecture

This is the statutory carve-out I shout from the rooftops to every structural engineer and architect client I have. IRC §199A(d)(2)(A) explicitly EXCLUDES engineering and architecture from the definition of an SSTB. Full stop. No phase-out, no matter how high your income (assuming you're otherwise a QTB). If you're an engineer with $600,000 of MFJ taxable income in 2026—$46,500 ABOVE the $553,500 phase-in end—you are NOT an SSTB. You are a non-SSTB QTB, subject only to the regular W-2/UBIA limitation. You still get a QBI deduction. Compare that to an accountant at the same income level—they're fully phased out and get zero. This is not a small difference; it's a multi-five-figure difference on a single return.

The Most Important Rule About SSTB Status

SSTB status applies ONLY when your taxable income is ABOVE the threshold. Below the threshold—Regime 1—SSTBs and non-SSTBs are treated identically. Full 20% deduction, no W-2/UBIA, no phase-out. I can't count how many new clients walk into my office in February convinced they're ineligible for QBI because they're a dentist, or a lawyer, or a consultant, when their income is well under the threshold. The SSTB label only matters once you cross $201,750 single or $403,500 MFJ in 2026. Below that, it's just a label with no tax consequence. Freelance service providers can estimate their QBI impact with the Freelance Annual Tax Calculator.

Source: IRS QBI Deduction FAQs

The $400 Minimum Deduction (New §199A(i))

Let's circle back to the new §199A(i) minimum deduction, because even though the dollar amount per return is modest, it's a philosophical shift in how Congress treats America's smallest business owners. Previously, a teenager mowing lawns in the summer who netted $900 on Schedule C would get a QBI deduction of $180 (20% of $900)—and that was it. Now, under §199A(i), the calculus changes.

The rule, again: If the aggregate QBI from all ACTIVE qualified trades or businesses is at least $1,000 for the tax year, then the taxpayer's combined QBI deduction from all sources (including REIT dividends and PTP income, which don't count toward the $1,000 threshold but are included in the overall deduction amount) cannot be less than $400. Stated differently: your total QBI deduction for the year is the GREATER of (A) the regular §199A calculation, or (B) $400—but only if you pass the $1,000 active-QTB-QBI gate.

Let's work through three microbusiness scenarios to see where this applies.

Scenario A: Single taxpayer with one active Schedule C business selling vintage postcards online. QBI = $1,200. No other business income. Regular calculation: 20% × $1,200 = $240. Taxable income cap: single taxpayer has $15,000 total income, so 20% × ($15,000 − $0 cap gain) = $3,000—plenty of room. So regular deduction = $240. Now check §199A(i): active QTB QBI is $1,200, which meets the ≥$1,000 threshold. So deduction = GREATER of ($240, $400) = $400. Result: $160 increase in deduction, worth $16–$35 depending on the bracket.

Scenario B: MFJ couple with three small active businesses. Business 1 (woodworking): $700 QBI. Business 2 (freelance editing): $500 QBI. Business 3 (farmers market preserves): $300 QBI. Combined active QTB QBI = $1,500. Regular deduction = 20% × $1,500 = $300. §199A(i): total active QBI ≥$1,000, so minimum $400 applies. Total deduction = $400.

Scenario C: Single taxpayer with $800 active Schedule C QBI plus $500 of passive rental property QBI (not active). Combined total QBI = $1,300—but the passive portion doesn't count toward the §199A(i) $1,000 active-QTB test. Since active QTB QBI is only $800 (< $1,000), the $400 minimum does NOT apply. Regular deduction = 20% × $1,300 = $260. Total deduction stays at $260.

Starting in 2027, the $400 minimum will be adjusted for inflation each year, same as the thresholds and standard deduction. The mechanics will be straightforward on the forms—the draft 2026 Form 8995 instructions I've reviewed from the IRS include a line specifically for the "§199A(i) minimum deduction comparison." Just make sure you don't accidentally include passive QBI or REIT/PTP income in your $1,000 active-QTB sum—those are explicitly excluded from the threshold test under §199A(i)(2)(A).

Form 8995 vs Form 8995-A — Which One Do YOU File?

This is another area where I see clients waste real money by using the wrong form—either they pay a tax preparer hundreds of dollars to file Form 8995-A when they could have done Form 8995 themselves in 15 minutes, or they try to force Form 8995 when they actually need 8995-A and miss out on deductions or get audited.

The IRS provides two forms for computing the QBI deduction, and the rule for choosing between them is actually very simple—it's entirely based on which regime you fall into. There is no choice, no election, no judgment call. The form follows your income.

Use the Simplified Form 8995 If: Your Taxable Income Is BELOW the Threshold (Regime 1)

If your taxable income before the QBI deduction is at or below $201,750 for single/HOH, or $403,500 for MFJ, in 2026, you file Form 8995. That's it. The simplified Form 8995 has three parts: Part I for your trade or business QBI (you just list each business's QBI or loss, no W-2/UBIA information needed), Part II for your REIT dividends and PTP income, and Part III to compute the combined deduction with the overall taxable income cap. No schedules. No SSTB designation. No aggregation elections. Form 8995 exists precisely because if you're in Regime 1, the complex limitations don't apply to you, and you shouldn't have to deal with them. About 70% of my pass-through clients in any given year are in Regime 1 and use Form 8995. If this is you, don't overcomplicate it.

Use Form 8995-A If: Your Income Is WITHIN or ABOVE the Phase-In Range (Regimes 2 and 3)

If your taxable income exceeds the threshold—any amount above $201,750 single/HOH or $403,500 MFJ in 2026—you must file Form 8995-A, the "Qualified Business Income Deduction Simplified Computation" form (the name is ironic, I know). Form 8995-A has four supporting schedules you may or may not need, depending on your situation: Schedule A for Specified Service Trades or Businesses (if you have any SSTBs and are anywhere above threshold), Schedule B for the W-2 Wages and UBIA of Qualified Property limitation (required for Regimes 2 and 3), Schedule C for Loss Carryforward from prior years, and Schedule D for the Aggregation Election (if you're aggregating multiple businesses under Reg. §1.199A-4). This is the form where you do the proration calculations, apply the SSTB phase-out, and reconcile the W-2/UBIA limitation per business. It's not rocket science, but it's also not the place to guess. If you're in Regime 2 or 3 and have multiple businesses, SSTB income, or complex W-2 allocations, this is where a CPA earns their fee. A word of warning: the IRS does match the W-2 wage numbers you report on Form 8995-A Schedule B against the W-2s filed by your business. Don't just guess at your W-2 numbers—pull the actual totals from your payroll reports or W-3.

Source: Form 8995 Instructions (check for the 2026 revision in late 2026)

Aggregation Election (Reg. §1.199A-4)

The QBI aggregation election is a powerful but widely misunderstood planning tool for taxpayers who own multiple pass-through businesses. In simple terms, aggregation allows you to pool multiple related non-SSTB qualified trades or businesses together and treat them as a single QTB for purposes of applying the W-2 wages and UBIA limitation, and the $400 minimum deduction's active-QTB test. The advantage? Combining W-2 wages and UBIA across businesses can often dramatically increase your allowable QBI deduction when the limitation applies (Regimes 2 and 3), compared to computing the limitation separately for each business.

Here's a classic example. Suppose you're a single-filer above the phase-in range with two wholly owned businesses: Business A is a high-QBI software consulting practice (non-SSTB if structured properly, or SSTB if classified as consulting—facts matter) that generates $500,000 of QBI but pays ZERO W-2 wages (you're the only person) and has $5,000 of UBIA (just a laptop). Business B is a related cloud hosting and infrastructure company that generates $50,000 of QBI, pays $200,000 of W-2 wages to its employees, and has $400,000 of UBIA in servers and networking equipment. If you compute the W-2/UBIA limitation separately, Business A's deduction is limited to the greater of $0 (50% × $0 W-2) or $125 (25% × $0 + 2.5% × $5,000) = $125. So Business A's deduction is $125 instead of $100,000 (20% × $500K)—you lose nearly the entire deduction. Business B's deduction is capped at the greater of $100,000 (50% × $200K) or $60,000 (25% × $200K + 2.5% × $400K) = $100,000, which is more than enough to cover its 20% × $50K = $10,000 deduction. But if you aggregate Business A and Business B as a single QTB under Reg. §1.199A-4, you get combined QBI of $550,000, combined W-2 of $200,000, and combined UBIA of $405,000. The limitation is now the greater of $100,000 (50% × $200K) or $60,125 (25% × $200K + 2.5% × $405K) = $100,000. The combined tentative QBI deduction is 20% × $550K = $110,000, limited to $100,000 by W-2/UBIA. Without aggregation: total deduction = $125 + $10,000 = $10,125. WITH aggregation: $100,000. That's an $89,875 difference. Just from checking a box on a form (and meeting the requirements, of course).

Aggregation Requirements (Must Meet All)

1. 50% Common Ownership: The same person or group of persons owns, directly or indirectly under §267(b) or §707(b), at least 50% of each trade or business being aggregated, for a majority of the tax year (including the last day of the year). A single individual owning 100% of two LLCs obviously satisfies this.
2. Same Tax Year: All trades or businesses use the same tax year end, determined without regard to short tax years. Calendar year + calendar year = OK. Calendar year + June 30 fiscal year = not OK.
3. Two of Three Operational Linkages: At least two of the following three must be true: (a) the businesses provide products, property, or services that are the same or customarily offered together (e.g., residential real estate brokerage + property management; restaurant + catering); (b) the businesses share facilities or significant centralized business elements, such as personnel, accounting, legal, manufacturing, purchasing, human resources, or IT; or (c) the businesses operate in coordination with or reliance upon one another as part of a larger integrated enterprise (e.g., supply chain interdependence).

The last rule to know about aggregation: ONCE MADE, THE ELECTION IS IRREVOCABLE going forward. You can add newly acquired or newly formed businesses to an existing aggregation group in later years, but you cannot disaggregate businesses you previously aggregated unless the facts and circumstances change dramatically (e.g., you sell one of the businesses, or the operational linkages disappear). This means the aggregation decision is not one to make lightly in December with a cocktail in hand. Run the numbers with your advisor. But if the businesses clearly qualify and the math works as overwhelmingly as it does in the example above, the election is a no-brainer.

Critical Note: QBI Reduces ONLY Federal Income Tax — NOT SE Tax, NIIT, or Additional Medicare

This is the #1 mistake I see in client meetings, tax preparation software inputs, and online financial forums. I'll shout this as loud as I can: THE QBI DEDUCTION DOES NOT REDUCE SELF-EMPLOYMENT TAX. It also does not reduce Net Investment Income Tax (NIIT, the 3.8% surtax on passive and certain investment income under §1411), nor does it reduce the 0.9% Additional Medicare Tax on earned income over $200K single/$250K MFJ under §3101(b)(2). The QBI deduction reduces ONLY your regular federal income tax liability. That's it.

Why is this distinction so important? Because self-employment tax is calculated on 92.35% of your net self-employment income from Schedule C or from partnership guaranteed payments and distributive shares of ordinary income. That 92.35% base (the statutory equivalent of the employer-side FICA deduction that W-2 employees don't see) is completely unaffected by the QBI deduction. If you have $200,000 of net SE income, your SE tax base is $184,700 regardless of whether you have a $40,000 QBI deduction or a $0 QBI deduction. The QBI deduction only enters the picture after AGI and deductions, when you're computing regular income tax on taxable income.

This also leads to a planning paradox that I walk through with every sole-proprietor client who is considering S-corporation status. The QBI deduction is calculated on QBI, which for a sole proprietor is approximately equal to net SE income. For an S-corp shareholder-employee, the reasonable compensation you pay yourself as W-2 wages is NOT QBI—only the remaining net business income after W-2 (the K-1 ordinary income) counts toward QBI. So an S-corp election often reduces your QBI base compared to a sole proprietorship. But the SE tax savings from the S-corp structure are usually much larger than the QBI reduction cost, especially above the Social Security wage base ($174,900 in 2026, per Rev. Proc. 2025-32). Use the Sole Proprietor Tax Calculator to see the separation between QBI (income tax reduction only) and SE tax (unchanged).

Entity Choice Planning: S-Corp vs Sole Proprietor in 2026 QBI World

The permanence of QBI under OBBBA finally lets us do meaningful multi-year entity choice analysis without the "QBI might expire" asterisk. Let's walk through the tradeoffs quickly, because this is the #1 planning question I get from clients earning between $80,000 and $500,000 of business income.

Sole Proprietor (or Single-Member LLC Disregarded Entity): The entire net business income flows to Schedule C. The entire net amount (times 92.35%) is subject to SE tax. The entire net amount (with minor adjustments like §179 and business interest addbacks) is QBI, so your QBI deduction base is maximized. Simplicity is the big advantage—no separate tax return, no payroll requirements, no reasonable compensation disputes. The big disadvantage is full SE tax exposure on every dollar up to the Social Security wage base.

S-Corporation (or LLC Electing S-Corp Tax Status): You must pay yourself a "reasonable" W-2 salary as an employee of the S-corp. That W-2 salary is subject to full FICA (Social Security + Medicare) with matching from the S-corp, so the employment-tax cost on the W-2 portion is effectively identical to SE tax on the same amount. But the remaining net business income—reported to you on Schedule K-1 as ordinary income—is NOT subject to SE tax. This is the S-corp's SE-tax advantage. The tradeoff on the QBI side: the W-2 reasonable compensation is NOT QBI, reducing your deduction base. But the W-2 wages you pay ARE W-2 wages for purposes of the W-2/UBIA limitation, which can help in Regimes 2 and 3. So there's a sweet spot where the SE tax savings from the S-corp structure outweigh the QBI deduction reduction. For most service businesses in 2026, that sweet spot tends to start around $100,000–$120,000 of net business income and goes up from there. At $300,000 of net income, the S-corp SE tax savings are usually in the $15,000–$20,000 range annually, while the QBI reduction from reasonable compensation might cost you $2,000–$4,000. The math is overwhelmingly in favor of S-corp at those income levels. But below $80,000, the payroll compliance costs and reasonable compensation requirements often make S-corp status not worth the hassle.

Remember that entity choice is a facts-and-circumstances decision, not a formula. State tax treatment of S-corps (franchise taxes, minimum taxes, S-corp recognition) varies wildly—Texas and California are very different from Florida or Wyoming in this regard. But QBI permanence means that once you run the numbers and decide, you don't have to rerun the analysis every 12 months wondering if QBI will survive.

FAQ

Sources and Additional Reading

• IRC §199A as amended by OBBBA §70105 (P.L. 119-21) — Full text of the One Big Beautiful Bill Act, including the QBI permanence, expanded phase-in ranges, and new $400 minimum deduction provisions.
• Rev. Proc. 2025-32 (IRB 2025-45) — Official IRS inflation adjustment procedure including the 2026 QBI threshold amounts ($201,750 / $403,500 / $201,775).
• IRS QBI Deduction FAQs — The IRS's own Frequently Asked Questions page for Section 199A, periodically updated as new guidance is issued.
• Form 8995 Instructions — Official IRS instructions for both Form 8995 (simplified) and Form 8995-A (with schedules). Always use the current-year revision for the tax year you're filing.