IRC §199A provides a 20% deduction on qualified MLP income — made permanent by the OBBBA. Qualified PTP income gets the full 20% deduction at every income level — without the W-2/UBIA limits or SSTB phase-out that gate non-PTP QBI above the income threshold. Five-MLP worked example, 10-year compounding, and the unresolved §751 question.
By Lucas Andersen — Last updated May 5, 2026
Section 199A provides a 20% deduction on qualified business income from pass-through entities, including PTPs and MLPs. This is a deduction, not a credit: $1,000 of QBI becomes $800 of taxable income. At a 37% marginal rate, the effective rate on QBI drops to 29.6%. Found on K-1 Box 20, code Z (with W-2 wages and UBIA reported on the supplemental statement that accompanies code Z). Note: Box 20 code AE is a different code (§163(j) Excess Taxable Income flowing to Form 8990) — not §199A QBI data. See the Box 20 Codes Reference for the full code map. Made PERMANENT by the OBBBA (signed July 4, 2025).
Qualified PTP income gets the full 20% deduction at every income level. Under §199A(a)(1)(B), qualified PTP income sits in its own bucket that does not route through the W-2 wage / UBIA test of §199A(b)(2)(B). It is also not subject to the SSTB phase-out. The income thresholds that gate non-PTP QBI above the limit simply do not apply to the qualified-PTP-income component of §199A.
This asymmetry actually favors PTP investors at higher income levels — not the other way around. Above the income threshold, an S-corp owner’s §199A deduction is limited to the greater of 50% of W-2 wages or 25% of W-2 wages plus 2.5% of UBIA — a low-wage business may keep only a fraction of the 20% deduction. SSTB owners (legal, medical, consulting practices) lose the deduction entirely above the threshold. A PTP investor with the same taxable income keeps the full 20% deduction on qualified PTP income — no W-2 test, no UBIA test, no SSTB phase-out, no income-based gate. The W-2 wages the MLP pays its employees and the billions in pipeline assets it owns are not factored into your personal deduction because they don’t need to be.
Statutory structure: §199A(a)(1)(A) covers the QBI component (subject to W-2/UBIA limits and SSTB rules above the threshold); §199A(a)(1)(B) covers the qualified PTP income component (a flat 20% with none of those limits). The two components are computed separately, then summed. §199A(c)(4)(C) provides that qualified PTP income is determined PTP by PTP, and §199A(b)(2)(B)’s W-2/UBIA limitation applies to the QBI component only — not to qualified PTP income.
The total §199A deduction is capped at 20% of (taxable income minus net capital gains). This applies to the sum of both buckets — the QBI component plus the qualified PTP income component — under §199A(a). It is a global lesser-of test against ordinary-income capacity, not a PTP-specific cliff. The qualified-PTP-income bucket itself is not gated by the income thresholds, but the combined deduction can still be reduced by this global cap at very high incomes with large net capital gains.
For most MLP investors with ordinary incomes that exceed their net capital gains, the global lesser-of cap is not binding — the cap floor is large enough to absorb the full §199A deduction. The cap only bites if net capital gains consume most of taxable income, which is an unusual fact pattern (e.g., a year with a large MLP sale generating significant LTCG, or a portfolio dominated by long-term equity gains).
Before the OBBBA, §199A was scheduled to sunset after 2025. This created a holding period calculus: long-term MLP projections had to model two scenarios. The OBBBA eliminated this uncertainty. The 20% deduction now compounds for the life of the hold — Year 1, Year 10, Year 30. For buy-and-hold MLP investors, this is a permanent structural benefit.
Important framing: the thresholds below apply to the non-PTP QBI component of §199A. They do NOT gate qualified PTP income, which receives the full 20% deduction at every income level. For MLP-only investors, the threshold is irrelevant unless you also have non-PTP QBI from another business or your total §199A deduction hits the global lesser-of test.
Thresholds for the non-PTP QBI component (2025): Single: ~$197,300 (phase-out begins) to ~$247,300 (fully phased out). MFJ: ~$394,600 to ~$494,600. Below the lower threshold, full 20% on the non-PTP QBI component; in the phase-out range, partial deduction subject to W-2/UBIA limit; above the upper threshold, W-2/UBIA limit applies in full and SSTBs phase out entirely. The threshold is based on taxable income (not AGI) — retirement contributions and itemized deductions reduce your number.
K-1 Box 20, code Z = your QBI. Calculated on Form 8995 or 8995-A. Each PTP is calculated separately — cannot combine QBI from EPD and ET. QBI losses from one PTP carry forward within that PTP only.
MFJ, $300,000 taxable income, $120,000 MLP portfolio. EPD ($30K): $750 QBI. ET ($30K): $550 QBI. MPLX ($25K): $600 QBI. WES ($20K): $400 QBI. PAA ($15K): -$150 QBI (carries forward). Total deductible QBI: $2,300. Deduction: 20% × $2,300 = $460. Tax savings at 24%: $110/year. Over 10 years (now permanent): ~$4,600 in cumulative deductions, ~$1,100 in tax savings. At 37%: ~$1,700 over 10 years.
Yes. The §199A deduction is based on your allocable QBI from the K-1 — it has no connection to your outside basis. Even if your basis has reached zero and distributions are taxable under §731(a), the partnership still allocates QBI to you and you still claim the 20% deduction on that QBI.
Can §199A apply to §751 recapture income on sale? This is actively debated among tax practitioners. The argument for: §751 income is ordinary income from a qualified trade or business. The argument against: recapture income may not be “income earned in the ordinary course.” The IRS has not issued definitive guidance. Consult your tax advisor — do not assume the deduction applies or doesn’t.