Section 179 Expensing: Limits and Qualifying Property

Section 179 of the Internal Revenue Code allows businesses to deduct the full purchase price of qualifying equipment and property in the year it is placed in service, rather than depreciating the cost over multiple years. This page covers the statutory deduction limits, the categories of property that qualify, the income-based phase-out rules, and how Section 179 compares to bonus depreciation rules. Understanding these boundaries matters because misclassifying property or exceeding applicable limits can trigger IRS adjustments and additional tax liability, as outlined in depreciation and amortization rules.

Definition and scope

Section 179 is codified at 26 U.S.C. § 179 and administered by the Internal Revenue Service. Its core function is to accelerate cost recovery: instead of capitalizing an asset and depreciating it under the Modified Accelerated Cost Recovery System (MACRS), a business may elect to expense the cost immediately, subject to annual dollar limits and a taxable-income ceiling.

For tax year 2023, the maximum Section 179 deduction was $1,160,000, with a phase-out threshold beginning at $2,890,000 in total qualifying property placed in service during the year (IRS Revenue Procedure 2022-38). These figures are adjusted annually for inflation under IRC § 179(b)(6). Once total qualifying property placed in service exceeds the phase-out threshold, the maximum deduction is reduced dollar-for-dollar, reaching zero when acquisitions hit approximately $4,050,000 for tax year 2023.

The deduction is available to sole proprietors, partnerships, S corporations, C corporations, and limited liability companies treated as any of the above for federal tax purposes. It is not available to individuals who have no business or trade activity, and it cannot create or increase a net operating loss — the deduction is capped at the taxpayer's aggregate taxable income from active business conduct (IRC § 179(b)(3)).

How it works

Making a Section 179 election follows a discrete sequence governed by IRS Form 4562 (Depreciation and Amortization):

1. Identify qualifying property placed in service during the tax year. The asset must be tangible personal property used more than 50 percent for business purposes.
2. Determine the business-use percentage. Only the business-use portion of an asset's cost is eligible. An asset used 70 percent for business yields an eligible cost equal to 70 percent of its purchase price.
3. Aggregate all Section 179 elections. Total elected amounts across all assets are summed and compared against the annual dollar cap ($1,160,000 for 2023).
4. Apply the phase-out reduction. If total qualifying property placed in service exceeds the phase-out threshold, reduce the maximum deduction dollar-for-dollar by the excess amount.
5. Apply the taxable-income limitation. The deduction cannot exceed aggregate net income from all active trades or businesses. Any disallowed amount carries forward to subsequent tax years indefinitely under IRC § 179(b)(3)(B).
6. Complete Form 4562, Part I, specifying each elected asset, its cost, and the elected deduction amount.
7. Attach Form 4562 to the business return — whether Form 1120, 1120-S, 1065, or Schedule C of Form 1040.

For business tax filing requirements, this election must be made on a timely filed return, including extensions. Amended returns may make or revoke a Section 179 election only with IRS consent under IRC § 179(c)(2).

Common scenarios

Tangible personal property is the most common category: machinery, equipment, computers, office furniture, and vehicles used in a trade or business. Passenger automobiles are subject to additional luxury auto limitations under IRC § 280F, which cap the Section 179 deduction on vehicles below 6,000 pounds gross vehicle weight. For tax year 2023, the first-year limit for a passenger automobile was $12,200 (IRS Rev. Proc. 2023-14), sharply lower than the general $1,160,000 ceiling.

Qualified improvement property (QIP) — interior improvements to nonresidential buildings placed in service after the building's original placed-in-service date — has been eligible for Section 179 since the Tax Cuts and Jobs Act of 2017 (Pub. L. 115-97). This includes HVAC systems, fire protection, alarm systems, and security systems when they serve a nonresidential building.

Listed property (including cameras, cell phones, and certain computers) requires that business use exceed 50 percent in the placed-in-service year. If business use drops to 50 percent or below in a subsequent year, recapture rules under IRC § 179(d)(10) require the taxpayer to include the excess deduction in gross income.

Off-the-shelf computer software is explicitly included as qualifying property under IRC § 179(d)(1)(A)(ii), provided it is not custom-developed and is subject to a nonexclusive license.

Real property — land, buildings, and structural components — is excluded from Section 179, with the narrow exception of QIP and specified improvements noted above. This contrasts with like-kind exchange 1031 treatment, which applies specifically to real property held for investment or business use.

Decision boundaries

Section 179 vs. Bonus Depreciation

The two mechanisms overlap but differ in critical ways:

Businesses with taxable income well above acquisition costs may find Section 179 and bonus depreciation interchangeable in effect. Businesses near or below breakeven often prefer bonus depreciation because it can produce or increase a net operating loss, whereas Section 179 cannot.

Interaction with pass-through entities

In partnerships and S corporations, the Section 179 deduction flows through to owners on Schedule K-1 but is subject to each owner's individual taxable-income limitation, not the entity's. The entity-level election on Form 4562 determines the amount allocated; the owner-level income test determines deductibility at the individual return stage. This interaction is covered in more detail under pass-through entity taxation.

Recapture risk

If a business ceases to use an asset in active trade more than 50 percent for business purposes before the end of its MACRS recovery period, recapture under IRC § 1245 requires the inclusion of previously deducted amounts in ordinary income. This recapture applies to both Section 179 and bonus depreciation deductions and is distinct from the capital gains treatment discussed in capital gains tax rules.

State conformity

State tax conformity with Section 179 varies. States that decouple from federal Section 179 limits — a common legislative choice — may impose lower caps or require addback of the excess federal deduction on the state return. Businesses operating in multiple states must evaluate each jurisdiction's conformity status separately; there is no single federal mandate requiring state adoption of the federal limit.

References

• 26 U.S.C. § 179 — Internal Revenue Code, Section 179 (Cornell Legal Information Institute)
• IRS Form 4562 and Instructions — Depreciation and Amortization
• IRS Publication 946 — How to Depreciate Property
• IRS Revenue Procedure 2022-38 — Inflation Adjustments for Tax Year 2023
• IRS Revenue Procedure 2023-14 — Luxury Auto Limits for 2023
• Tax Cuts and Jobs Act of 2017, Pub. L. 115-97 (Congress.gov)
• IRS Instructions for Form 4562 — Section 179 Election Details