Tax

QBI (Section 199A) Deduction: The Full Walkthrough

The 20% pass-through deduction has SSTB phase-outs, wage and UBIA limits, REIT/PTP rules, and aggregation elections. Here's the complete framework, not the surface version.

By Aparna Devalla, CPA4 min · 5 slidesUpdated June 15, 2026

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The Two-Tier Framework

Below the income threshold ($241,950 single / $483,900 MFJ in 2026): simple — 20% × min(QBI, taxable income before QBI), regardless of business type.
Above the threshold: complex. SSTBs phase out entirely; non-SSTBs are limited by W-2 wages paid and UBIA (unadjusted basis immediately after acquisition) of qualified property.
Phase-in range: $50K above threshold for single, $100K for MFJ. Within the range, partial deduction with proportional SSTB phase-out and proportional wage/UBIA limit.
Above the phase-in fully: SSTBs get nothing; non-SSTBs get the lesser of 20% × QBI OR the wage/UBIA limit.

SSTB — Specified Service Trade or Business

Categories: health, law, accounting, actuarial, performing arts, consulting, athletics, financial services, brokerage, investing, investment management.
Catch-all: any trade where the principal asset is the reputation or skill of an owner.
What's NOT SSTB: engineering, architecture, real estate (most), most product/services businesses.
Test is applied per-activity, not per-entity. A consulting firm that also does software resale: split the income.

The Wage and UBIA Limit (Non-SSTBs Above Threshold)

Allowed QBI deduction is limited to the GREATER of: (a) 50% of W-2 wages paid by the business, OR (b) 25% of W-2 wages + 2.5% of UBIA of qualified property.
(b) helps businesses heavy on real property (rental, retail, manufacturing) where wages alone are low but capital investment is high.
UBIA = original cost basis, NOT adjusted (depreciation doesn't reduce it for this calculation). Includes building, equipment, computers, furniture.
Tracks property for the longer of (i) 10 years or (ii) the depreciable recovery period.

Aggregation — Combining Activities

Multiple trades or businesses can be aggregated to share wages and UBIA across activities — boosting the limit calculation.
Requirements: same person/group owns 50%+ of each, same tax year ends, all are non-SSTBs, and they're functionally integrated.
Aggregation election made on Form 8995-A; binding for the entity once made (and on all subsequent years unless facts change).
Strategic value: a property-rich activity (high UBIA, low wages) can boost the limit on a wage-light service activity.

REITs, PTPs, and Cooperatives

REIT dividends qualify for 20% deduction without SSTB or wage limits — simpler than business QBI.
Publicly Traded Partnership (PTP) income qualifies similarly.
Combined REIT + PTP deduction sits separately from QBI in the calculation — own tracks.
Specified Cooperatives (agricultural, horticultural) have their own §199A(g) rules — coordinate carefully.
Need a QBI analysis tied to your specific facts? Rubric Financial models QBI as part of annual tax planning — including the wage/UBIA optimization and aggregation elections.

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