Section 179 Roof Replacement Deduction: Caps, Rules, and Recapture

A roof replacement on a nonresidential commercial building can qualify for the Section 179 roof replacement deduction, letting you write off the full cost in the year the new roof is placed in service instead of depreciating it over 39 years. For 2026, you can expense up to $2,560,000 under Section 179, which covers almost any commercial roofing project in a single tax year. The building has to be used in your trade or business, the roof has to be a capital improvement to an existing structure, and a few other conditions apply.¹

Which Roofs Qualify

Section 179 was expanded to cover a short list of improvements to commercial buildings, called “qualified real property.” Roofs are named explicitly in the statute, alongside HVAC, fire protection, and security systems.¹ That inclusion is what makes a one-year write-off possible. A roof your business owns clears the eligibility bar if all of the following are true:

The building is nonresidential real property. Warehouses, offices, retail stores, and manufacturing facilities qualify. Apartment buildings, duplexes, and single-family rentals do not.
The roof is placed in service after the building itself was first placed in service. The original roof on new construction is not qualified real property; the rule targets replacements and upgrades to existing buildings.¹
You use the building predominantly in your trade or business. The IRS reads “predominantly” as more than 50% business use, and mixed-use buildings get the deduction prorated.²
The work is a capital improvement, not routine maintenance. A full tear-off and replacement is a restoration that qualifies. Patching shingles or sealing a leak is maintenance, which gets deducted differently.
The roof is finished and functional before the end of your tax year. A project that straddles year-end is not deductible until the year it is actually placed in service.

The line between a capital improvement and maintenance can be gray on partial work. A cosmetic overlay of a still-functional roof is murkier than a complete replacement, and the specific facts control.

2026 Dollar Caps and the Income Limit

The One Big Beautiful Bill Act permanently raised Section 179 limits for property placed in service in tax years beginning after 2024, with inflation adjustments after 2025.¹ For 2026:

The maximum Section 179 deduction is $2,560,000 across all qualifying property placed in service during the year.
The phase-out threshold is $4,090,000. Every dollar of qualifying purchases above that figure reduces the $2,560,000 cap dollar-for-dollar. Spend $6,650,000 or more on qualifying assets in the year, and the Section 179 deduction phases out entirely.

There is also a separate income cap. Your Section 179 deduction cannot exceed the total taxable income from your active trades and businesses for the year. If your combined business income is $200,000 and the new roof cost $350,000, you can only deduct $200,000 against this year’s return.¹

The $150,000 you could not use carries forward indefinitely. It keeps its character as a Section 179 deduction and can be applied against business income in any future year, subject to that year’s limits.

Residential Rentals Are Excluded

Landlords get tripped up here. Section 179 qualified real property is limited to nonresidential buildings, so a new roof on an apartment complex, duplex, or rental house cannot be expensed under Section 179 no matter how actively you manage the property.¹ For residential rental buildings, a roof replacement is still a capital improvement, but it is depreciated over 27.5 years using the straight-line method.³ Bonus depreciation generally does not apply either, because the roof is treated as part of the building rather than as separate personal property.

How to Claim the Deduction

You claim Section 179 on IRS Form 4562, “Depreciation and Amortization,” filed with your business tax return for the year the roof is placed in service.⁴ Part I handles the election. Enter the roof cost on the line for qualified real property, and the form walks through the dollar cap, phase-out reduction, and income limit to arrive at your allowed deduction. The final figure flows from Form 4562 to your business return.

The Election Deadline Is Tight

Section 179 must be elected on the original tax return for the year the property is placed in service. Miss it, and you have a narrow window to fix the omission: you can still make the election on an amended return filed within six months of the original due date, not counting extensions.⁵ After that window closes, the election is gone for that asset in that year.

Revoking the Election

You can revoke a Section 179 election after making it, but the revocation itself is irrevocable.¹ You get one chance to change your mind. If you revoke the election on a roof, you cannot re-elect Section 179 for that asset later; you would depreciate it over 39 years instead, or use bonus depreciation if it still qualifies.

Recapture If Business Use Drops or You Sell

If business use of the building falls to 50% or below in any year after you took the deduction, the IRS claws back part of the benefit. The recapture equals the difference between what you deducted under Section 179 and what you would have deducted through normal depreciation over the same period, and you report it as ordinary income on Part IV of Form 4797.⁶

Selling the building triggers similar treatment. Any gain attributable to the Section 179 deduction is recaptured as ordinary income rather than taxed at capital gains rates. On a roof that cost hundreds of thousands of dollars, the recapture can be substantial, which is worth factoring in if you are considering a sale or a change of use within a few years of the replacement.

Section 179 Versus Bonus Depreciation

Bonus depreciation is the other route to a fast write-off, and the One Big Beautiful Bill Act permanently restored 100% bonus depreciation for qualifying property acquired and placed in service after January 19, 2025. The earlier phase-down (80% in 2023, 60% in 2024) no longer applies. With both provisions now allowing a full first-year write-off, the differences are mechanical:

Section 179 is capped at your active business income for the year. Bonus depreciation has no such cap and can create or deepen a net operating loss.
Section 179 is elective and asset-by-asset, giving you precise control over how much you deduct. Bonus depreciation applies automatically to all eligible property in an asset class unless you opt out.⁷
Section 179 is applied first. If any cost remains after hitting the dollar cap or income limit, bonus depreciation can absorb the leftover.

For a business with steady income, both provisions produce the same bottom-line result on a roof: the full cost deducted in year one. The choice matters more when income is tight, when you want to preserve a loss position, or when you want to expense some assets and depreciate others.

Watch Your State Tax Return

Not every state follows the federal Section 179 rules. Some cap the deduction well below the federal figure or tie their calculation to an older version of the tax code. California, for example, limits Section 179 to $25,000 regardless of the federal amount. The result is that you can deduct the full roof cost on your federal return and still spread it over many years on your state return. Check your state’s conformity rules before assuming the state benefit matches the federal one.

1
Office of the Law Revision Counsel. 26 USC 179 – Election to Expense Certain Depreciable Business Assets
2
Internal Revenue Service. Instructions for Form 4562
3
Internal Revenue Service. Depreciation and Recapture 4
4
Internal Revenue Service. About Form 4562, Depreciation and Amortization
5
Internal Revenue Service. Rules for Making a Section 179 Election (INFO 2001-0200)
6
Internal Revenue Service. Instructions for Form 4797
7
Internal Revenue Service. Additional First Year Depreciation Deduction (Bonus) – FAQ