Section 179 Deduction 2026: Limits, Rules, and Planning Strategies

The One Big Beautiful Bill Act (OBBBA, enacted July 4, 2025) permanently raised the Section 179 expensing limit to $2,500,000 — more than double the prior-law ceiling — and reset the phase-out threshold to $4,000,000. Inflation-adjusted for 2026, the amounts are $2,560,000 maximum deduction and $4,090,000 phase-out threshold (IRS Publication 946, 2026 edition). Because Section 179 and restored 100% bonus depreciation now apply concurrently, most equipment and qualified improvement property can be fully expensed in year one — but the income limitation unique to Section 179, the phase-out for large-volume buyers, and widespread state non-conformity require deliberate election sequencing to avoid unexpected tax outcomes.

What Changed Under OBBBA

Before OBBBA, the Section 179 limit for tax years beginning in 2025 was $1,250,000 (IRS Rev. Proc. 2024-40), scheduled to adjust for inflation under TCJA indexing. OBBBA amended IRC §179(b)(1) to set the limit at $2,500,000 and the investment limitation at $4,000,000, both indexed annually. For 2026, inflation adjustments produce a $2,560,000 limit and $4,090,000 phase-out threshold; the phase-out eliminates the deduction entirely when total qualifying property placed in service reaches $6,650,000.

OBBBA simultaneously restored 100% first-year bonus depreciation under IRC §168(k) for qualified property placed in service on or after January 20, 2025, permanently halting the TCJA phase-down schedule that had reduced the rate to 60% in 2024. The two mechanisms are not mutually exclusive — they are sequenced, with Section 179 applied first and bonus depreciation applied to remaining basis — and together allow immediate expensing of virtually any business property acquisition.

Why does Section 179 still matter when 100% bonus depreciation is available? Three reasons: (1) Section 179 applies to used property without the "original use" or "no prior basis" restrictions that apply to some bonus depreciation scenarios; (2) Section 179 is the appropriate tool when a client makes a selective opt-out from bonus depreciation for a property class; and (3) their income limitation rules differ — Section 179 cannot create a net loss, while bonus depreciation can. For clients near the phase-out threshold, Section 179 provides precision deduction sizing that bonus depreciation cannot.

Qualifying Property

Section 179 property must be tangible personal property (or certain enumerated real property) placed in service during the tax year for active use in a trade or business.

Tangible personal property: Machinery, equipment, computers, vehicles (subject to the SUV cap discussed below), and office furniture used in business. The property must generate §1245 gain on disposition — structural real property components do not qualify in their standard form.

Qualified real property (five categories added by the TCJA, retained by OBBBA): Section 179 may be elected for: (a) qualified improvement property (QIP — interior improvements to existing nonresidential buildings, excluding enlargements and structural components); (b) roofs; (c) HVAC equipment; (d) fire protection and alarm systems; and (e) security systems. This matters for clients who lease commercial space — tenant improvements that don't qualify as QIP under the technical test (for example, improvements to the building shell or landlord-owned fixtures) may still qualify under one of the five enumerated categories.

Off-the-shelf computer software: Commercially available software not substantially modified for the specific purchaser qualifies for Section 179. Subscription-based SaaS typically does not qualify because the client holds a license, not the underlying property.

Used property: Section 179 applies to used tangible personal property acquired from an unrelated party with no restriction on prior use or prior basis — unlike bonus depreciation, which requires the taxpayer not to have previously held depreciable basis in the specific property. A client purchasing a used delivery van, used manufacturing machine, or used medical equipment can elect Section 179 for the full acquisition price.

Property that does not qualify:

• Residential rental property and nonresidential real property outside the five enumerated categories
• Property used predominantly outside the United States (IRC §168(g))
• Property held for investment rather than active business use
• Property acquired from a related party (IRC §179(d)(2) — same rules as bonus depreciation)
• Custom software and intangibles (these follow amortization schedules)

The Income Limitation: The Critical Constraint Section 179 Has That Bonus Depreciation Does Not

IRC §179(b)(3) limits the Section 179 deduction to the taxpayer's aggregate net income from all active trades or businesses in the year. Income from wages, passive activities, and investment portfolios does not count toward the floor. A business client with $400,000 in net trade or business income can elect up to $400,000 in Section 179 regardless of the $2.56M ceiling — and cannot elect $500,000 in Section 179 even if the purchase qualifies and the ceiling permits it.

Excess Section 179 that exceeds business income carries forward indefinitely under §179(b)(3)(B), preserving its character as a Section 179 deduction in the carryforward year and applying automatically when future-year business income permits it. This differs from a net operating loss: the carryforward is not subject to the 80% limitation applicable to NOLs under §172. It simply waits until income allows it.

For clients with volatile income — construction, staffing, seasonal businesses — the income limitation creates planning risk: a large Section 179 election in a down year produces no benefit and a carryforward that can only be used in future high-income years. Bonus depreciation, which has no income floor, is often the safer deduction vehicle in these situations. For clients with stable, high income, Section 179 produces identical results to bonus depreciation while offering more selective application.

Phase-Out for Large Equipment Buyers

The phase-out operates dollar-for-dollar: for every dollar of qualifying Section 179 property placed in service above $4,090,000, the deduction limit falls by one dollar.

The phase-out is permanent within the tax year — there is no carryforward for the phased-out amount. For high-volume capital buyers (manufacturers, equipment lessors, construction businesses placing $6M+ of qualifying property annually), Section 179 produces zero benefit and bonus depreciation is the exclusive immediate-expensing mechanism.

For clients projecting total qualifying property near the phase-out threshold, the planning question is whether year-end additions should be accelerated into or deferred out of the current year. The tradeoff: if the client is approaching $4.09M and adding another $500,000 of equipment would push them to $4.59M, their available Section 179 deduction drops to $2,060,000 — meaning the $500,000 addition costs them $500,000 of Section 179 capacity but those costs are still immediately expensed via bonus depreciation. The net tax result is the same only if the client's state conforms to bonus depreciation, which many do not.

Heavy Vehicle and SUV Cap

Section 179(b)(5) limits the deduction for sport utility vehicles to $32,000 for 2026 (IRS Rev. Proc., 2026 inflation adjustment; $31,300 in 2025). The $32,000 cap applies to any SUV with GVWR over 6,000 pounds. It does not apply to:

• Pickup trucks with an open cargo bed of at least six feet
• Cargo vans designed primarily for cargo transport
• Vehicles with seating for more than eight passengers behind the driver
• Ambulances, hearses, and commercial vehicles meeting specific use tests

A client purchasing a 2026 Ford F-250 (GVWR approximately 10,000 lbs, full-size open bed) for business use can elect Section 179 for the full purchase price. A client purchasing an equivalent-weight Chevrolet Suburban classified as an SUV is capped at $32,000. For clients acquiring vehicles, identifying GVWR and cargo bed configuration before year-end is necessary to model the actual deduction.

Note that the separate luxury auto limitation under IRC §280F still caps first-year depreciation on passenger automobiles (GVWR 6,000 lbs or less), regardless of any Section 179 election. The §280F and §179(b)(5) limits operate in different weight classes and address different vehicle categories.

Election Sequencing With Bonus Depreciation

The regulations under Treas. Reg. §1.168(k)-2 specify the order in which elections are applied:

1. Section 179 is elected first. The client designates which property and how much cost is expensed under Section 179, subject to the $2.56M ceiling and the business income limitation.
2. Bonus depreciation applies to the remaining adjusted basis. After Section 179 reduces the basis of the elected property, 100% bonus depreciation applies to that remaining basis — and to any other qualifying property for which Section 179 was not elected.
3. MACRS regular depreciation covers any remaining adjusted basis (uncommon when both elections are available and applicable).

For most clients with income sufficient to absorb Section 179, this sequence produces full expensing in year one regardless of which election is applied first. The sequence matters when: (a) the client has used Section 179 for property in a state that conforms to Section 179 but not bonus depreciation (maximizing the state deduction while minimizing the federal bonus depreciation that the state adds back); or (b) the client is selectively applying Section 179 to avoid using bonus depreciation on property whose accelerated depreciation would reduce the QBI deduction by more than the deduction benefit.

For the full election sequencing strategy — including which property classes to apply Section 179 versus bonus depreciation to optimize state conformity — see How to Apply Bonus Depreciation and Section 179 for Business Clients in 2025.

State Conformity

Most states do not conform to the OBBBA-elevated Section 179 limit or to 100% bonus depreciation. State non-conformity creates permanent planning complexity for multi-state businesses and businesses in non-conforming states.

California: Section 179 deduction limited to $25,000 (no inflation adjustment); investment limitation $200,000. Federal deductions above these amounts are added back on the California return and depreciated under California's own MACRS schedule. California does not conform to bonus depreciation. A California-based business that takes the full federal Section 179 deduction of $2.56M on equipment will recognize $2.535M of California addback income in the same year and recover it over the California MACRS recovery period.

New York: Conforms to a higher Section 179 limit but requires the amount above a fixed threshold to be spread over three years on the New York return, creating a timing difference rather than a permanent addback.

Illinois, New Jersey, Minnesota: Generally conform to the federal Section 179 limit but do not conform to bonus depreciation, requiring a bonus depreciation addback with recovery over the state MACRS schedule.

Conforming states: A number of states have enacted legislation to conform to OBBBA's Section 179 increase or have floating conformity to the federal Code. Verify each state's current conformity status via the relevant state department of revenue before projecting net state tax impact.

Planning implication: When a client operates in high-tax non-conforming states, the state addback can materially reduce the net present value of federal Section 179 and bonus depreciation deductions. For clients with significant California exposure, modeling the combined federal/state benefit — not just the federal deduction — is necessary for accurate planning.

Interaction With the QBI Deduction

Section 179 deductions reduce the qualified business income (QBI) of the business in which the property is used, since QBI is calculated after deducting all ordinary business expenses including depreciation. This matters for clients subject to the W-2 wage and qualified business asset investment (QBAI) limitation under §199A(b)(2)(B).

The QBAI component of the limitation uses the unadjusted basis immediately after acquisition of qualified property — this figure is not reduced by the Section 179 election. A client who elects Section 179 for machinery retains the machinery's full original cost in the QBAI calculation for the year of acquisition, even though the depreciable basis has been reduced to zero. This asymmetry means Section 179 elections can be modeled favorably for clients in the QBI wage/property phase-in range.

However, the reduction in QBI itself reduces the tentative §199A deduction from the 23% rate times QBI. Whether the QBAI benefit offsets the QBI reduction depends on the specific mix of W-2 wages and property basis. The full interaction analysis for clients near the §199A phase-in threshold is covered in QBI Deduction in 2025: How Section 199A Works After OBBBA.

FAQ

What is the Section 179 deduction limit for 2026?

The 2026 Section 179 limit is $2,560,000, with a phase-out beginning at $4,090,000 of total qualifying property and eliminating the deduction entirely at $6,650,000. These are inflation-adjusted from the OBBBA base amounts of $2,500,000 and $4,000,000 set for 2025.

Can Section 179 create a net operating loss?

No. IRC §179(b)(3) limits the deduction to aggregate net income from the taxpayer's active trades or businesses. Any Section 179 in excess of business income carries forward indefinitely as a Section 179 deduction — it does not convert to an NOL. Bonus depreciation under §168(k) has no income floor and can generate a net operating loss available for carryforward under IRC §172.

Does Section 179 apply to used equipment?

Yes, without restriction on prior use. A client who purchases used manufacturing equipment, used vehicles, or used computers from an unrelated party can elect Section 179 for the full purchase price. Bonus depreciation, by contrast, requires the taxpayer not to have previously held a depreciable interest in the specific property.

What is the SUV cap for Section 179 in 2026?

The cap is $32,000 for sport utility vehicles with GVWR over 6,000 pounds placed in service in 2026. Pickup trucks with qualifying open cargo beds, cargo vans, and vehicles seating more than eight behind the driver are not subject to this limitation.

How do Section 179 and cost segregation work together?

Cost segregation reclassifies long-lived building components (39-year nonresidential real property) into 5-year, 7-year, or 15-year personal property or land improvements — making them eligible for Section 179 or bonus depreciation. For clients acquiring or renovating commercial real estate, combining a cost segregation study with a Section 179 or bonus depreciation election in the acquisition year routinely produces the highest single-year tax benefit available. For methodology and candidacy assessment, see Cost Segregation Studies: When They're Worth It and How to Execute Them.

Is off-the-shelf software eligible for Section 179?

Yes. Commercially available software purchased (not subscribed to) qualifies for Section 179 expensing as tangible personal property equivalent, provided it is not a §197 intangible (custom software). Perpetual software licenses purchased from vendors for standard business applications — accounting software, practice management platforms, design tools — qualify. Annual SaaS subscriptions generally do not qualify because the taxpayer holds only a license, not depreciable property.

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