Section 179 may let a business expense qualifying property when placed in service. Learn eligibility, limits, carryovers, and California differences.
The Section 179 deduction is an election that may allow a taxpayer to expense some or all of the cost of qualifying business property in the year it is placed in service instead of recovering that cost solely through depreciation. It can accelerate a deduction, but it does not make every purchase deductible or guarantee that the entire elected amount is currently allowed.
Section 179 differs from regular MACRS depreciation and bonus depreciation. A taxpayer chooses the qualifying property and elected amount, applies the annual dollar and investment limits, and then applies a taxable-income limitation. Any qualifying amount disallowed by the business-income limit may generally carry forward, subject to later-year rules.
Qualifying property generally includes eligible tangible personal property acquired for use in the active conduct of a trade or business. Certain off-the-shelf computer software and elected qualified real property may also qualify federally. Qualified real property can include qualified improvement property and specified improvements to nonresidential real property, such as roofs, HVAC, fire-protection and alarm systems, and security systems, when the statutory requirements are satisfied.
Land, most buildings, property held only for investment, and property acquired from certain related persons generally do not qualify. Special restrictions apply to property used outside the United States, leased property, mixed-use property, and property converted from personal use. The taxpayer should classify the actual asset rather than relying on a vendor's marketing claim that a purchase is "Section 179 eligible."
For tax years beginning in 2025, the maximum federal Section 179 deduction is $2,500,000, with the limitation reduced dollar for dollar when total Section 179 property placed in service exceeds $4,000,000. For tax years beginning in 2026, Publication 946 lists a $2,560,000 maximum and a $4,090,000 phaseout threshold. A separate annual limit applies to certain sport utility vehicles: $31,300 for 2025 and $32,000 for 2026.
These are ceilings, not automatic deductions. The elected amount cannot exceed eligible basis and can be reduced by the investment phaseout. The current deduction is also limited to taxable income from the active conduct of trades or businesses, calculated under the applicable rules. Entity-level and owner-level limitations can both matter for pass-through businesses.
Property must be placed in service during the tax year. Paying for or receiving an asset is not enough if it is not ready and available for its assigned business use. A machine delivered December 20 but not installed and operational until January 8 is generally placed in service in January, so the election belongs to the later tax year.
For listed property, qualified business use generally must exceed 50% to claim Section 179. If a $30,000 vehicle is used 70% for qualified business use, no more than $21,000 of cost enters the initial Section 179 analysis before the vehicle, income, and other limits. Commuting is personal use, even when the vehicle displays a business logo.
If business use later falls to 50% or less, part of a prior Section 179 deduction may have to be recaptured as income. Contemporaneous mileage and use records are therefore important throughout the asset's life.
Section 179 is elective asset by asset and is subject to the taxable-business-income limit. Bonus depreciation follows separate eligibility, timing, and election rules and is not subject to that same income limit. The order of calculations generally matters: Section 179 is applied before bonus depreciation and regular MACRS to the remaining basis.
Federal law now generally allows 100% bonus depreciation for qualifying property acquired and placed in service after the applicable January 19, 2025 transition rules, but that does not make Section 179 obsolete. Section 179 may permit more targeted deduction planning, and some property eligible for Section 179 may not receive the same bonus treatment. Elections should be modeled rather than chosen merely for the largest first-year federal deduction.
California's limits are dramatically lower. For 2025, FTB guidance generally limits the California Section 179 deduction to $25,000 and begins the dollar-for-dollar phaseout when qualifying property placed in service exceeds $200,000. California also does not conform to every federal eligibility rule, including federal treatment of off-the-shelf computer software, and does not conform to federal bonus depreciation.
A federal deduction can therefore exceed the California deduction by a large amount. Maintain separate federal and California basis, depreciation, carryover, and disposition schedules. Individuals may use FTB Form 3885A and Schedule CA when a depreciation adjustment is required; entity forms vary.
Heath Income Tax can help compare Section 179, bonus depreciation, regular depreciation, and the related California adjustments before an election is filed.
Can Section 179 create a business loss?
The deduction is generally limited by taxable income from active trades or businesses. An otherwise allowable amount restricted by that limit may carry forward.
Must the business pay cash for the property?
Not necessarily. Qualifying purchased property can be financed, but it still must meet the ownership, eligibility, business-use, and placed-in-service requirements.
Is Section 179 always the best choice?
No. A business may benefit more from preserving deductions for future years, using bonus or regular depreciation, or avoiding a California mismatch. The best pattern depends on projected income and disposition plans.
The definitions and examples on this page are for informational purposes only and do not constitute tax advice. Tax laws change frequently and individual circumstances vary. Consult a qualified tax professional before making decisions based on this content.
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