The Section 179 deduction is one of the most valuable tax benefits available to businesses that purchase equipment, machinery, or other qualifying property. Instead of spreading the cost of an asset over several years through standard depreciation, Section 179 allows a business to deduct the entire purchase price in the year the asset is placed into service. For companies making capital investments, understanding how the Section 179 deduction works, and how it compares to bonus depreciation, can lead to significant tax savings.
This guide answers the central question business owners ask at year-end: how much can you deduct, what property qualifies, and when does Section 179 beat the alternatives? The rules are set out in Section 179 of the Internal Revenue Code and explained in IRS Publication 946, and the answers below reflect those primary sources.
What is the Section 179 deduction?
Section 179 is a provision in the U.S. tax code that permits businesses to expense the full cost of certain tangible property in the year it is purchased and put to use. Congress originally designed this tax break to encourage small and mid-sized businesses to invest in themselves by removing the wait associated with multi-year depreciation schedules.
Under normal depreciation rules, a business that buys a $500,000 piece of equipment would deduct a portion of that cost each year over the asset’s useful life, often five, seven, or even fifteen years. Section 179 collapses that timeline. If the asset qualifies, the business can write off the entire $500,000 in year one, reducing taxable income immediately.
This immediate write-off makes Section 179 especially attractive for businesses that need to manage cash flow carefully. By accelerating the deduction, a company can reinvest the tax savings into operations, hiring, or additional equipment purchases sooner rather than later.
What property qualifies for Section 179?
Eligible property under Section 179 includes a broad range of tangible business assets. To qualify, the property must be purchased (not leased from another party) and placed into service during the tax year in which the deduction is claimed. The asset must also be used for business purposes more than 50% of the time.
Commonly qualifying assets
Many fixed assets qualify for this write-off. These include:
- Furniture and fixtures: desks, chairs, shelving, and display cases used in offices or retail spaces.
- Computer equipment and software: servers, workstations, laptops, and off-the-shelf software purchased for business use.
- Machinery and equipment: manufacturing tools, construction equipment, and specialized industry machinery.
- Certain vehicles: cars, trucks, vans, and SUVs used for business, though passenger vehicles are subject to additional dollar caps.
- Qualified improvement property: nonresidential roofs, HVAC systems, fire protection and alarm systems, and certain interior improvements to commercial buildings.
Asset-heavy operations tend to benefit most from this provision. Companies in manufacturing and construction, for example, routinely place large machinery and equipment into service and can use Section 179 to recover those costs in the same year the spending occurs.
Property that does not qualify
Real property such as land and most buildings cannot be expensed under Section 179. Inventory held for resale, property used outside the United States, and assets acquired from related parties are also excluded. Additionally, property used 50% or less for business purposes does not meet the eligibility threshold.
Section 179 deduction limits and phase-out thresholds
Unlike bonus depreciation, the Section 179 tax deduction comes with annual dollar limits that cap how much a business can expense. These limits are adjusted each year for inflation.
Current limits after the One Big Beautiful Bill Act
The One Big Beautiful Bill Act, signed into law on July 4, 2025, roughly doubled the Section 179 limits for tax years beginning after December 31, 2024. For 2025, the maximum allowable deduction rose to $2.5 million, and the phase-out threshold, the total amount of qualifying property a business can purchase before the deduction begins to shrink, rose to $4 million.
These amounts continue to be indexed for inflation. For 2026, the maximum deduction is $2.56 million and the phase-out threshold is $4.09 million, as set out in Revenue Procedure 2025-32. The IRS publishes the current inflation-adjusted figures each year in the Instructions for Form 4562, so confirm the amount for the tax year you are filing.
Once total qualifying purchases exceed the phase-out threshold, the available deduction decreases dollar for dollar. If a business purchases more than the combined limit (threshold plus maximum deduction), Section 179 is no longer available for that tax year.
The taxable income limitation
A critical restriction that distinguishes Section 179 from other depreciation methods is the taxable income limitation. A business cannot use Section 179 to create or increase a net operating loss. The deduction is limited to the company’s taxable income from all active trades or businesses. Any Section 179 amount that exceeds taxable income can be carried forward to future years, but it cannot generate a loss in the current year.
This rule means that unprofitable businesses or those with minimal taxable income may not be able to take full advantage of Section 179 in a given year, even if they made significant qualifying purchases.
Section 179 vs bonus depreciation: key differences
Section 179 depreciation and bonus depreciation both allow businesses to accelerate deductions for qualifying assets, but they operate under different rules and serve different strategic purposes.
How bonus depreciation reached 100%
When Congress passed the Tax Cuts and Jobs Act of 2017, it expanded bonus depreciation to allow a 100% immediate write-off for eligible property purchased and placed in service between late 2017 and the end of 2022. Because bonus depreciation had no dollar cap and could generate a loss, it became the default strategy for many businesses, and Section 179 saw less use during those years.
The phase-out that was reversed
Beginning in 2023, bonus depreciation entered a scheduled phase-out. The allowable percentage dropped to 80% in 2023 and 60% in 2024, and it was set to continue declining toward zero by 2027. The One Big Beautiful Bill Act ended that decline. It restored 100% bonus depreciation on a permanent basis for qualifying property acquired and placed in service after January 19, 2025, eliminating the scheduled reductions for 2025 and beyond.
With 100% bonus depreciation reinstated, businesses again have a no-cap option for fully expensing most qualifying purchases in year one. Section 179 and bonus depreciation now work alongside each other, and many businesses will use both depending on their taxable income position and the size of their capital spending.
When to choose one over the other
Section 179 lets a business choose exactly how much to expense, asset by asset, which is useful for fine-tuning taxable income and preserving deductions for future years. Bonus depreciation applies broadly to eligible asset classes, has no dollar cap, and can create or increase a loss. In many cases, the optimal strategy uses both: apply Section 179 selectively where the income limitation and per-asset flexibility matter, then rely on 100% bonus depreciation for the remaining qualifying assets.
Who cannot use Section 179?
While Section 179 is broadly available, certain entities face restrictions. Non-grantor trusts and estates cannot claim this deduction. Additionally, businesses that exceed the spending phase-out threshold lose the benefit entirely for that tax year.
Partnerships and S corporations can elect Section 179 at the entity level, but the deduction passes through to individual partners or shareholders, where it remains subject to the taxable income limitation on each owner’s personal return. This pass-through treatment can create complications when owners have varying levels of income from other sources.
Planning ahead: the future of Section 179
With the One Big Beautiful Bill Act in place, both Section 179 and bonus depreciation now rest on more stable footing than they have in years. The higher Section 179 limits are permanent and indexed for inflation, and 100% bonus depreciation is no longer scheduled to phase out. That stability makes both tools reliable inputs for multi-year capital planning rather than moving targets.
Businesses planning significant capital expenditures should still evaluate their projected taxable income and total asset purchases for the current year, because the income limitation and phase-out threshold continue to shape how much Section 179 actually delivers. Working with a CPA or tax advisory team to model the interplay between Section 179, bonus depreciation, and standard depreciation schedules can yield substantial savings.
The most effective approach is to review equipment and property needs before year-end, confirm which assets qualify, and structure the timing of purchases to maximize the available deduction in the current tax year.
Frequently Asked Questions
How does Section 179 work?
Section 179 allows a business to deduct the full purchase price of qualifying equipment or property in the tax year it is placed into service, rather than depreciating the cost over multiple years. The deduction is limited to the business’s taxable income and is subject to annual dollar caps that adjust for inflation.
What qualifies for Section 179?
Qualifying property includes tangible assets such as machinery, equipment, furniture, computer hardware and software, certain vehicles, and qualified improvement property like HVAC systems and nonresidential roofs. The asset must be purchased and used more than 50% for business purposes during the tax year.
What is the Section 179 limit?
For 2025, the maximum deduction under Section 179 is $2.5 million, and the phase-out begins when total qualifying property purchases exceed $4 million. For 2026, those amounts rise with inflation to $2.56 million and $4.09 million. These limits adjust annually and are set independently from bonus depreciation allowances.
What is the difference between Section 179 and bonus depreciation?
Section 179 has an annual dollar cap and cannot create a net operating loss, while bonus depreciation has no dollar limit and can generate a loss. The One Big Beautiful Bill Act restored 100% bonus depreciation on a permanent basis for property placed in service after January 19, 2025, so both tools now allow full first-year expensing under different rules.
Can Section 179 create a tax loss for my business?
No. This deduction cannot exceed the taxable income of the business in the year it is claimed. If the elected amount is greater than taxable income, the excess carries forward to future tax years. This is one of the key differences between Section 179 and bonus depreciation.
Does Section 179 apply to vehicles?
Yes, certain business vehicles qualify for Section 179, including trucks, vans, and SUVs with a gross vehicle weight rating above 6,000 pounds. However, passenger vehicles are subject to additional luxury auto limitations that cap the first-year deduction, so the full Section 179 amount may not be available for lighter vehicles.
