Section 179 Roof Replacement Deduction: Limits, Election, and Recapture

A roof replacement on a nonresidential commercial building can be fully written off in the year it is placed in service under the Section 179 roof replacement deduction. For 2026, you can expense up to $2,560,000 of qualifying property, which covers most commercial roofing projects in a single tax year.¹ The building has to be used in your trade or business, the roof has to be a replacement rather than part of original construction, and the deduction is capped by your business income for the year.

Which Roofs Qualify

Section 179 covers a specific category the statute calls qualified real property. Roofs are named in that category alongside HVAC, fire protection and alarm systems, and security systems, so a roof replacement on the right kind of building can be expensed in full instead of depreciated over the standard 39-year period for nonresidential real property.¹

Four conditions have to line up:

The building is nonresidential real property. Warehouses, offices, retail, and manufacturing facilities qualify.
The roof is placed in service after the building itself was first placed in service. Roofs installed as part of the original construction of a new building do not qualify as qualified real property.
You use the building predominantly in your trade or business, meaning more than 50% business use. Mixed-use buildings prorate the deduction to the business-use percentage.²
The work is a capital improvement, not maintenance. A full tear-off and replacement clearly qualifies. Patching leaks or replacing a few shingles is maintenance and is deducted differently. A cosmetic overlay of a still-functional roof falls in a grayer area where the facts control.

The roof also has to be completed and placed in service before your tax year ends. A project that runs past December 31 is not deductible until the year the roof is actually functional.

Residential Rentals Are Excluded

Landlords often assume Section 179 works for their properties. It doesn’t. Qualified real property is limited to nonresidential buildings, so a new roof on an apartment complex, duplex, or single-family rental cannot be expensed under Section 179 no matter how actively you manage the property.¹

On residential rentals, the roof is still a capital improvement, but it depreciates over 27.5 years using the straight-line method.³ Bonus depreciation generally doesn’t rescue you here either, because the roof is treated as part of the building rather than separate personal property.

2026 Dollar Limits and the Income Cap

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 numbers are:

Maximum deduction: $2,560,000 across all Section 179 property placed in service during the year.
Phase-out threshold: $4,090,000. Once total qualifying purchases exceed that figure, the maximum deduction drops dollar for dollar. Spend $6,650,000 or more on qualifying assets and the Section 179 deduction is gone entirely.

Separately, your total Section 179 deduction for the year cannot exceed the taxable income from all of your active trades or businesses. If your combined business income is $200,000 and the new roof cost $350,000, only $200,000 comes off this year.¹

The remaining $150,000 carries forward indefinitely and keeps its character as a Section 179 deduction, so a lean year does not cost you the write-off. You just use it against business income in a future year, subject to that year’s own limits.

Section 179 or Bonus Depreciation

Bonus depreciation is the other route to a same-year write-off. The One Big Beautiful Bill Act permanently restored 100% bonus depreciation for qualifying property acquired and placed in service after January 19, 2025, ending the phase-down that had reduced the percentage in prior years.

For a stable, profitable business, both provisions produce the same result on a roof: full deduction in year one. The mechanics differ in ways that can matter:

Section 179 cannot exceed active business income; bonus depreciation has no such cap and can create or deepen a net operating loss.
Section 179 is elective on an asset-by-asset basis, so you choose what to expense and how much. Bonus depreciation applies automatically to all eligible property in an asset class unless you opt out.⁴
Section 179 is applied first. Anything left over after hitting its dollar cap or income cap can then be covered by bonus depreciation.

The choice matters most when income is tight, when you want to control the size of a loss, or when you want to selectively expense some assets while depreciating others.

How to Make the Election

You claim the deduction on IRS Form 4562, “Depreciation and Amortization,” filed with your business return for the year the roof is placed in service.⁵ Part I handles Section 179. You enter the roof cost on the qualified real property line, and the form applies the dollar limitation, investment-limit reduction, and income cap to arrive at your allowed deduction.

The election must be made on the original return for the year the property is placed in service. If you filed on time and forgot, you have a narrow window: an amended return within six months of the original due date, not counting extensions.⁶ After that, the election for that property in that year is gone.

You can revoke an election you made, but the revocation itself is irrevocable.¹ Revoke it and you cannot later re-elect Section 179 for that same roof. You would depreciate it over 39 years instead, or claim bonus depreciation if it still qualifies.

Recapture If Things Change

If business use of the building drops to 50% or below in any year after you took the Section 179 deduction, the IRS recaptures part of the benefit. The recaptured amount is the difference between what you expensed under Section 179 and what normal depreciation would have given you over the same period. You report it as ordinary income on Part IV of Form 4797.⁷

Selling the building triggers the same treatment. Gain attributable to the Section 179 deduction is recaptured as ordinary income rather than taxed at capital gains rates. On a six-figure roof, that swing can be significant, so factor it in if a sale or a change in use is on the horizon.

Check Your State Rules

Not every state follows federal Section 179. California caps the deduction at $25,000 regardless of the federal number. Other states tie their limits to pre-OBBBA federal figures or run their own phase-out math. You may end up expensing the full roof federally and depreciating it over many years on your state return. Confirm your state’s conformity rules before you count on the same result on both.

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. Additional First Year Depreciation Deduction (Bonus) – FAQ
5
Internal Revenue Service. About Form 4562, Depreciation and Amortization
6
Internal Revenue Service. Rules for Making a Section 179 Election (INFO 2001-0200)
7
Internal Revenue Service. Instructions for Form 4797