The Section 179 deduction is one of the most valuable depreciation tax breaks available to small and mid-size businesses. Manufacturers, distributors, and other capital-intensive companies that invest heavily in equipment, technology upgrades, and leasehold improvements can use this provision to immediately write off qualifying purchases rather than spreading the cost over many years. Understanding how Section 179 works alongside bonus depreciation can significantly reduce your current-year tax liability and free up cash for reinvestment.
For years, Congress treated many of these depreciation tax breaks as temporary “extender” provisions, forcing businesses to guess whether the rules would be renewed before year-end. The Protecting Americans from Tax Hikes (PATH) Act of 2015 changed that dynamic by permanently extending several key breaks and locking in higher spending thresholds. Two later laws, the Tax Cuts and Jobs Act of 2017 (TCJA) and the One Big Beautiful Bill Act of 2025 (OBBBA), expanded these provisions even further. The result is a far more predictable planning environment for companies that rely on fixed-asset investments to grow.
This article explains how the Section 179 deduction works, how bonus depreciation works, how the limits have changed over time, and what businesses need to know to plan their equipment purchases strategically.
How the Section 179 Deduction Works for Business Equipment
The Section 179 deduction allows businesses to expense the full purchase price of qualifying fixed assets in the year they are placed in service, rather than depreciating them over their useful life. This applies to tangible personal property such as machinery, equipment, computers, and off-the-shelf software. The IRS sets out the governing rules and recovery periods in Publication 946, How to Depreciate Property.
The dollar limits on Section 179 have risen substantially over the past decade. The PATH Act permanently set the deduction limit at $500,000, with a phase-out threshold of $2 million in total qualifying purchases. The TCJA then raised those amounts to $1 million and $2.5 million for property placed in service after December 31, 2017, both indexed for inflation. Most recently, the OBBBA increased the limit to $2.5 million with a $4 million phase-out threshold for property placed in service in tax years beginning after December 31, 2024.
For tax year 2026, those amounts are inflation-adjusted to a $2,560,000 maximum deduction and a phase-out beginning at $4,090,000 of total purchases, according to the IRS in Revenue Procedure 2025-32. Once total qualifying purchases exceed the threshold, the deduction phases out dollar for dollar. One important restriction has remained constant: the Section 179 deduction cannot reduce a business’s taxable income below zero, so it cannot create a net operating loss on its own.
Because the limit, the threshold, and the inflation indexing are now permanent parts of the tax code, businesses can plan multi-year capital programs with far more confidence than they could before 2016.
Section 179 Deduction Limit and Qualified Leasehold Improvements
One of the lasting changes from the PATH Act involves qualified leasehold improvements. Previously, businesses that renovated leased commercial spaces generally had to depreciate those improvements over a 39-year straight-line recovery period. The PATH Act permanently set a 15-year recovery period for qualified leasehold improvements, making many renovations far more tax-efficient.
This change is particularly relevant for manufacturers and distributors who lease warehouse, production, or office space and need to modify it for operational requirements. A 15-year recovery period means substantially higher annual depreciation deductions compared to the old 39-year schedule, improving cash flow during the years when the improvement is generating the most value.
The treatment of building interior improvements has continued to evolve. The TCJA created a single “qualified improvement property” (QIP) category, and a later technical correction assigned QIP a 15-year recovery period, which made it eligible for bonus depreciation. Businesses should keep detailed records of improvement costs and confirm that each project meets the IRS definition of a qualifying improvement. Work with a tax advisor to ensure proper classification, since misclassifying an improvement can result in lost deductions or penalties.
Bonus Depreciation: A Complement to Section 179
Bonus depreciation serves a different purpose than Section 179, and the two programs can work together to maximize depreciation tax breaks in a single year. While the Section 179 deduction has a spending cap and cannot create a taxable loss, bonus depreciation has no spending threshold and can generate a net operating loss.
The bonus depreciation rate has changed repeatedly. Under the PATH Act, businesses could claim 50% first-year bonus depreciation for qualifying assets placed in service from 2015 through 2017, with the rate scheduled to step down to 40% in 2018 and 30% in 2019. The TCJA overrode that schedule, raising the rate to 100% for qualifying property acquired and placed in service after September 27, 2017, and before January 1, 2023. The IRS summarizes the TCJA changes in its guidance on new rules and limitations for depreciation and expensing.
Under the TCJA, the 100% rate then began a phasedown: 80% in 2023, 60% in 2024, 40% in 2025, and 20% in 2026. The OBBBA changed course again, permanently restoring 100% bonus depreciation for qualifying property acquired and placed in service after January 19, 2025. Because the rate depends on when an asset is acquired and placed in service, businesses should verify the figure that applies to their specific purchase with a tax professional.
A key distinction is that bonus depreciation historically applied only to new assets, not used equipment. The TCJA expanded eligibility to include used property that is new to the purchasing business, and the OBBBA preserved that broad scope. As always, the applicable percentage and eligibility criteria depend on the year an asset is placed in service.
Bonus Depreciation vs. Section 179: Choosing the Right Strategy
Deciding between bonus depreciation and the Section 179 deduction depends on the size of your purchases, your taxable income, and your long-term tax planning goals. Each program has distinct advantages that make it better suited to certain situations.
Section 179 gives the business direct control over how much to expense, since the election is optional and can be applied selectively to specific assets. That control is useful when a business wants to deduct just enough to reach a target taxable income rather than zero it out, or when it wants to preserve deductions for a future higher-income year.
Bonus depreciation is generally more advantageous when a business has very large capital investments, when its purchases exceed the Section 179 phase-out threshold, or when it wants to create a taxable loss that can be carried forward. Companies that buy more than the Section 179 limit in qualifying assets in a single year will see that deduction phase out, making bonus depreciation the primary tool for accelerated write-offs on the excess.
Many businesses use both programs in the same tax year. A typical strategy is to apply the Section 179 deduction first to selected assets, then claim bonus depreciation on the remaining qualifying property. This layered approach can dramatically reduce or eliminate current-year tax liability on capital investments.
How Fixed Asset Depreciation Rules Affect Tax Planning
The permanent extension of higher Section 179 limits removed a major source of uncertainty from business tax planning. Before the PATH Act, the Section 179 deduction had been scheduled to revert to just $25,000 with a $200,000 investment threshold, real estate improvements faced uncertain treatment, and the bonus depreciation program was set to expire.
That uncertainty caused many manufacturers and distributors to delay fixed-asset purchases at year-end while waiting for Congress to renew the extender provisions. With permanent and now larger limits in place, businesses can make equipment purchasing decisions based on operational needs and long-term strategy rather than legislative speculation.
Effective tax planning around depreciation still requires careful timing. Qualifying assets must be placed in service, not merely ordered, by the last day of the tax year to be eligible for that year’s deductions. For pass-through entities such as partnerships and S corporations, additional rules govern how depreciation deductions flow through to individual owners and partners.
Businesses that plan major equipment purchases should model the tax impact of different depreciation strategies before committing. The interaction between Section 179, bonus depreciation, state-level conformity rules, and the specific year an asset is placed in service can produce significantly different after-tax costs depending on the approach taken.
Work with a Tax Advisor Before Purchasing Fixed Assets
The depreciation tax breaks available under current law represent a substantial opportunity, but various restrictions apply. The rules around Section 179, bonus depreciation, and improvement property are detailed and subject to change through new legislation. Qualified assets must meet specific IRS criteria, and the timing of when assets are placed in service directly affects eligibility.
Before making significant fixed-asset purchases, consult with a qualified tax team. The tax advisory services team at Pease Bell can model different scenarios, ensure your purchases qualify for the deductions you expect, and help structure transactions to maximize your tax benefit within current law.
Frequently Asked Questions
What qualifies for a Section 179 deduction?
Tangible personal property used in business qualifies for the Section 179 deduction, including machinery, equipment, computers, off-the-shelf software, and certain improvements to nonresidential real property. The asset must be purchased and placed in service during the tax year, and it must be used for business purposes more than 50% of the time.
What is the Section 179 deduction limit?
The limit has risen over time: it was permanently set at $500,000 under the 2015 PATH Act, raised to $1 million by the 2017 TCJA, and increased to $2.5 million by the 2025 OBBBA. For tax year 2026 the inflation-adjusted maximum is $2,560,000, with a phase-out beginning at $4,090,000 in total qualifying purchases. Once total purchases exceed the threshold, the available deduction decreases dollar for dollar.
What is the difference between bonus depreciation and Section 179?
Section 179 lets businesses choose which assets to expense up to the annual limit and cannot reduce taxable income below zero. Bonus depreciation applies to all qualifying assets with no spending cap and can create a net operating loss. Many businesses use both in the same year to maximize their write-offs.
Can you use Section 179 on used equipment?
Yes. Section 179 has always been available for both new and used equipment, as long as the asset is new to the purchasing business. Bonus depreciation was historically limited to new assets, but the TCJA expanded it to cover qualifying used property, and that broader eligibility remains in place. Check the IRS rules for the tax year in question.
How do you calculate the Section 179 deduction?
Start with the total cost of qualifying assets placed in service during the tax year. Deduct up to the annual limit, which is $2,560,000 for 2026. If total qualifying purchases exceed the phase-out threshold ($4,090,000 for 2026), reduce the available deduction dollar for dollar by the excess amount. The remaining deduction cannot exceed the business’s taxable income for the year.
Does bonus depreciation apply to leasehold improvements?
Qualified leasehold improvements generally use a 15-year recovery period that was made permanent by the PATH Act, which is significantly shorter than the previous 39-year schedule. Under current law, qualified improvement property may also be eligible for bonus depreciation. Consult a tax advisor to determine which benefits apply to your specific renovation project.
