We have reached the year mark since President Trump signed the One Big Beautiful Bill Act into law, and for commercial property owners, real estate investors, and innovation-driven businesses, the landscape has shifted considerably. Some of what the bill delivered was genuinely good news. Some of it came with a tighter clock than many expected. And at least one provision left a real gap in the tax code that Congress is still working to address.
As we mark the one-year anniversary, here is a grounded look at where certain tax strategies stand today, what has changed, and what you may still be leaving on the table.
Cost Segregation and Bonus Depreciation: The Opportunity Is Real and It Is Permanent
Of all the provisions in the One Big Beautiful Bill, the restoration of 100% bonus depreciation may be the one that gets the most attention from commercial real estate professionals, and for good reason. Prior to the bill’s passage, bonus depreciation had been phasing out under the Tax Cuts and Jobs Act. Property owners were looking at 40% in 2025, 20% in 2026, and nothing after that. The bill reversed that trajectory entirely.
For qualified property acquired or newly constructed after January 19, 2025, 100% bonus depreciation is now back and, more importantly, it is now permanent. That is not a temporary extension or a multi-year patch. Barring future legislative change, full first-year expensing is the new baseline going forward.
There is one transitional nuance worth noting. Property placed in service between January 1 and January 19, 2025, as well as property acquired on or before January 19, 2025 and placed in service after that date, is still subject to the old phase-down schedule. If that applies to any of your assets, a qualified advisor can help you understand exactly where you stand.
What this means practically is that cost segregation studies have never been more powerful as a planning tool. A well-executed study identifies personal property components within a commercial building that can be reclassified to shorter depreciable lives, typically five, seven, or fifteen years instead of the standard 27.5 or 39. When those reclassified assets are placed in service and eligible for 100% bonus depreciation, the first-year deduction can be substantial. For property owners who have recently acquired, constructed, or renovated commercial real estate, completing a cost segregation study before year-end is one of the clearest tax planning moves available right now.
The bill also raised the Section 179 expensing cap to $2.5 million, with a phase-out beginning at $4 million, which creates additional planning flexibility for eligible businesses investing in depreciable property.
R&D Tax Credits: Relief Arrived, But Some Deadlines Have Already Passed
For businesses that invest in qualified research and development activities, the One Big Beautiful Bill brought meaningful and long-overdue relief. The most significant change involves the treatment of research and experimental expenditures under Internal Revenue Code Section 174.
Starting with tax years beginning after December 31, 2024, companies can once again deduct their domestic R&D costs in the year they are incurred. This is a return to the rule that existed prior to 2022, when the Tax Cuts and Jobs Act required those costs to be capitalized and amortized over five years instead. That amortization requirement caused real pain for many businesses, particularly smaller and mid-sized companies that depend on R&D activity as a core part of their operations.
The new provision, codified under Section 174A, also addressed the years when mandatory amortization was in effect. Businesses still carrying unamortized R&D balances from 2022, 2023, or 2024 have two options: deduct the remaining balance all at once in 2025, or spread it across 2025 and 2026.
For smaller businesses, defined as those with average annual gross receipts under $31 million for the 2022 to 2024 period, the bill created an opportunity to amend prior-year returns and recover taxes paid on costs that were capitalized under the old rules. That amended return deadline was July 4, 2026, meaning if you have not already pursued that path, it is worth a conversation with your tax advisor immediately to determine whether anything can still be done.
One important clarification: the 15-year amortization requirement for foreign R&D expenditures was not changed by the bill. That remains in effect.
The R&D Tax Credit itself, separate from the expensing rules, was made permanent under the One Big Beautiful Bill. For companies across manufacturing, construction, engineering, software development, agriculture, and dozens of other industries, this permanence removes the uncertainty that used to cloud multi-year planning. If your business is solving technical problems, improving processes, or developing new products or formulas, there is a reasonable chance you are leaving R&D credits unclaimed. A no-cost analysis with CSSI can help identify whether your activities qualify.
Section 179D: A Closing Window, a Retroactive Opportunity, and a Bill Worth Watching
This is where the One Big Beautiful Bill created the most complexity, and frankly, the most urgency. Section 179D, the Energy Efficient Commercial Buildings Deduction, has been one of the most valuable incentives available to building owners, designers, architects, and engineers working on energy-efficient commercial construction and retrofits. Under the Inflation Reduction Act, the deduction could reach up to $5.81 per square foot when prevailing wage and apprenticeship requirements are met.
The One Big Beautiful Bill did not repeal 179D outright, but it set a hard termination date. Section 179D now does not apply to any property on which construction begins after June 30, 2026. For projects that broke ground before that date, eligibility is preserved assuming all other technical and certification requirements are satisfied. For anything that has not yet begun construction, the deduction is no longer available under current law.
There are two important counterpoints to that headline, and both deserve attention.
The first is retroactivity. Many building owners and project teams do not realize that 179D can be claimed retroactively for qualifying projects going back to 2006. If your building was constructed or retrofitted during that period and the 179D deduction was not taken at the time, you may be able to capture it today without filing amended returns. Retroactive claims, sometimes called lookback studies, are filed using IRS Form 3115 with Designated Change Number 152, which generates a catch-up deduction through a Section 481(a) adjustment on your current year return. This is a legitimate and IRS-recognized process that has helped many property owners recover meaningful deductions they did not know they had missed.
The second is legislation. The sunset of 179D has not gone unnoticed on Capitol Hill. In April 2026, Congressman Brian Fitzpatrick of Pennsylvania introduced the American Energy Dominance Act with bipartisan support and backing from North America’s Building Trades Unions. Among its provisions is a proposal to restore Section 179D as a permanent deduction without any sunset or expiration date. The bill has not been enacted, and current law remains in effect, but its introduction reflects genuine legislative interest in preserving energy-efficiency incentives for commercial construction. It is worth monitoring, particularly for developers and designers with projects in the pipeline.
For now, the most actionable path is straightforward. If you have projects that began construction before June 30, 2026, confirm your eligibility and get the required energy certification and documentation in order. If you have older projects where 179D was never claimed, a lookback study through CSSI can determine whether a Form 3115 catch-up is available. And if you are watching the Fitzpatrick bill or similar efforts, staying informed through a knowledgeable advisor is the best way to respond quickly if the legislative landscape shifts.
The Bottom Line
One year after the One Big Beautiful Bill became law, the tax landscape looks meaningfully different for commercial property owners and businesses that invest in innovation. Permanent 100% bonus depreciation paired with cost segregation creates a powerful planning combination. Restored R&D expensing removes years of frustration and opens real refund opportunities for eligible small businesses. And while the sunset of 179D represents a real loss, retroactive claims and active legislative efforts mean the story is not over.
At CSSI, we have been helping clients navigate exactly this kind of shifting environment for over 23 years. Whether you are evaluating a recent acquisition, reviewing years of unclaimed deductions, or trying to understand what the next round of legislative changes might mean for your business, we are here to help you make sense of it. Start with a no-cost analysis, and let us show you what may still be available.
Frequently Asked Questions
What is the One Big Beautiful Bill Act?
The One Big Beautiful Bill Act is a sweeping piece of tax legislation signed into law on July 4, 2025. It made several major changes to the tax code, including the permanent restoration of 100% bonus depreciation, a reversal of the mandatory R&D amortization rules, and the introduction of a sunset date for the Section 179D energy-efficient building deduction.
Does 100% bonus depreciation apply to my property?
For most qualified property acquired or newly constructed after January 19, 2025, yes. Property with an acquisition or construction date on or before January 19, 2025 may still be subject to the old phase-down schedule. A cost segregation study can help you identify exactly which assets qualify and how much you can deduct.
Can I still claim R&D tax credits for prior years?
Potentially. Smaller businesses with average gross receipts under $31 million for 2022 through 2024 may have been eligible to amend prior-year returns for significant refunds. If you have not explored this yet, speak with a CSSI specialist as soon as possible to understand your options.
Is Section 179D completely gone?
Not entirely. The deduction is still available for projects where construction began on or before June 30, 2026. Additionally, qualifying buildings constructed or renovated as far back as 2006 may be eligible for a retroactive claim using Form 3115, with no amended returns required. If you have never claimed 179D on a prior project, it is worth finding out whether something was missed.
What is Form 3115 and how does it relate to 179D?
Form 3115 is an IRS form used to request a change in accounting method. For Section 179D purposes, it allows building owners to claim a missed deduction retroactively as a catch-up adjustment on their current-year return, without needing to file amended returns for prior years. CSSI handles this process as part of a lookback study.
Could Section 179D come back?
There is active legislative interest in restoring it. Congressman Brian Fitzpatrick introduced the American Energy Dominance Act in April 2026, which would reinstate 179D as a permanent deduction with no expiration date. The bill has bipartisan support but has not been enacted. We are monitoring it closely and will keep clients informed as it develops.
How do I know if I qualify for any of these incentives?
The best first step is a no-cost analysis with CSSI. Our team will review your property, business activity, and prior filings to identify what may be available to you, at no charge and with no obligation.
