One Year After the One Big Beautiful Bill Act: What Commercial Property Owners and Business Leaders Need to Know Now

TL;DR: One year after the One Big Beautiful Bill Act was signed into law, three tax strategies need your attention now — 100% bonus depreciation is permanent, R&D expensing is back, and Section 179D has a cutoff date that's already passed. Some deadlines are gone. Others are still open. Here's what I'm seeing out in the field.

• 100% bonus depreciation is permanent for qualified property placed in service after January 19, 2025.

• Cost segregation studies now generate significantly stronger first-year returns because of that permanence.

• R&D expensing is restored for tax years beginning after December 31, 2024 — and the R&D Tax Credit itself is now permanent.

• Section 179D no longer applies to projects where construction began after June 30, 2026 — but retroactive claims going back to 2006 are still available.

• The amended return deadline for eligible small businesses to recover capitalized R&D costs was July 4, 2026.

I'm David Wiener, CEO of Cash Flow Strategies, Inc. and host of the Tax Strategy Playbook podcast. I've spent the past year helping clients figure out what this law actually means in practice — not in theory, not in headlines, but in real results. What I keep finding is that the opportunity is bigger than most people know, and the window on some of it is closing faster than most advisors are letting on.

What Is 100% Bonus Depreciation — and Why Does Permanence Matter?

Of all the changes in this bill, the return of 100% bonus depreciation gets the most attention from commercial real estate professionals — and it deserves it. Before the bill passed, bonus depreciation was being slowly reduced under the Tax Cuts and Jobs Act: 40% in 2025, 20% in 2026, and nothing after that. The One Big Beautiful Bill reversed that completely.

For qualified property bought or newly built after January 19, 2025, 100% bonus depreciation is now permanent. This isn't a short-term fix or a temporary patch — unless Congress changes it again, full first-year write-offs are now the standard. That's a very different world than what we were dealing with eighteen months ago.

There's one transition detail worth knowing. Property placed in service between January 1 and January 19, 2025 — and property bought on or before January 19, 2025 but placed in service after that — still follows the old phase-down rules. If any of your assets fall in that window, a qualified advisor can walk you through exactly where you stand.

Key Point: Permanent 100% bonus depreciation changes the math on almost every commercial real estate purchase going forward. Properties that didn't make sense for a cost segregation study before often do now.

How Does Cost Segregation Work With 100% Bonus Depreciation?

A cost segregation study looks at the parts of a commercial building that can be moved to shorter depreciation schedules — typically five, seven, or fifteen years instead of the standard 27.5 or 39. When those reclassified assets qualify for 100% bonus depreciation, the first-year write-off can be huge. The cost of the study doesn't go up. The return on it does.

The numbers speak for themselves. On a $1 million commercial property, a cost segregation study often produces $40,000 to $60,000 in tax savings in the first year alone. A typical study costs around $10,000 — which works out to an immediate 4x to 6x return on that investment. That's not a small rounding error. That's a real advantage sitting inside the tax code, waiting to be used.

The savings vary by property type. Furnished short-term rentals reclassify about 63% more depreciable value than unfurnished single-family rentals. Year-one federal tax savings on a $500,000 short-term rental come in at roughly $43,695 at the 37% bracket. That same $500,000 unfurnished single-family rental yields about $25,740. A medical office at the same value produces about $49,119.

For property owners who've recently bought, built, or renovated commercial real estate, finishing a cost segregation study before year-end is one of the clearest tax moves available right now. The bill also raised the Section 179 expensing limit to $2.5 million, with a phase-out starting at $4 million — which gives eligible businesses more options when investing in depreciable property.

Key Point: Cost segregation paired with permanent 100% bonus depreciation is producing some of the strongest first-year results I've seen in over two decades. Properties that didn't justify a study before now often make strong financial sense under the current rules.

R&D Tax Credits: What Changed, What's Permanent, and What You Missed

For businesses that invest in qualified research and development, the One Big Beautiful Bill brought relief that was a long time coming. The biggest change involves Internal Revenue Code Section 174. Starting with tax years that begin after December 31, 2024, companies can deduct their domestic R&D costs in the same year they spend the money.

Before 2022, that was the standard rule. Then the Tax Cuts and Jobs Act required those costs to be spread out and deducted over five years instead. That change caused real financial pain — especially for smaller and mid-sized businesses where R&D isn't a side project, it's the core of what they do. The new law fixes that.

Key Point: Restored R&D expensing removes years of built-up frustration for businesses that were essentially penalized for investing in new ideas. Getting back to same-year deductibility is the kind of steady, compounding fix that makes a real difference over time.

What About Unamortized R&D Balances From 2022 to 2024?

The new rule, written into Section 174A, covers the years when mandatory amortization was active. Businesses still holding unamortized R&D balances from 2022, 2023, or 2024 had two choices: deduct the full remaining balance in 2025, or split it across 2025 and 2026.

For smaller businesses — those with average annual gross receipts under $31 million for 2022 through 2024 — the bill created a chance to amend past returns and get back taxes paid on costs that were forced into amortization under the old rules. That deadline was July 4, 2026. If you haven't looked into this yet, talk to your tax advisor right away to find out if anything can still be done.

One key clarification: the 15-year amortization requirement for foreign R&D costs was not changed by this bill. That rule is still in effect.

Is the R&D Tax Credit Permanent?

Yes — the R&D Tax Credit, which is separate from the expensing rules, was made permanent under the One Big Beautiful Bill. For companies in manufacturing, construction, engineering, software, farming, and many other fields, that permanence takes away the uncertainty that used to make multi-year planning difficult. The IRS estimates over 20,000 businesses claim more than $20 billion in Section 41 credits each year. On average, companies earn 12 to 16 cents in federal and state credits for every qualified dollar spent on R&D.

If your business is solving technical problems, improving how things work, or building new products or formulas, there's a good chance you're leaving R&D credits unclaimed. A no-cost review can show you whether your work qualifies.

Key Point: Now that R&D credits are permanent, businesses can build real multi-year strategies around them — instead of claiming them one year at a time and hoping the rules don't change.

Section 179D: What's the Current Status of the Energy Efficient Buildings Deduction?

This is where the One Big Beautiful Bill created the most confusion — and the most urgency. Section 179D, the Energy Efficient Commercial Buildings Deduction, has been one of the best incentives available to building owners, designers, architects, and engineers working on energy-efficient commercial buildings and upgrades. Under the Inflation Reduction Act, the deduction went up to $5.81 per square foot when prevailing wage and apprenticeship rules were met.

The One Big Beautiful Bill didn't get rid of 179D entirely, but it did set a firm end date. Section 179D no longer applies to any property where construction starts after June 30, 2026. Projects that broke ground before that date are still eligible — as long as all other technical and certification requirements are met. For anything that hasn't started yet, the deduction isn't available under current law.

Can I Still Claim 179D for Older Projects?

Many building owners don't know that 179D can be claimed retroactively for qualifying projects going back to 2006. If your building was built or renovated during that time and you never claimed the 179D deduction, you may still be able to get it today — without filing amended returns.

These retroactive claims — sometimes called lookback studies — are filed using IRS Form 3115 with Designated Change Number 152. That filing creates a catch-up deduction through a Section 481(a) adjustment on your current-year return. It's a legitimate, IRS-recognized process that has helped many property owners recover deductions they didn't even know they'd missed.

For 2026, Section 179D offers up to $5.94 per square foot for projects that meet Prevailing Wage and Apprenticeship requirements. On a 100,000 square foot warehouse or office building, that's nearly $600,000 in immediate tax relief. Designers working on government-owned or tax-exempt buildings often miss this — the tax-exempt owner can transfer the deduction to the lead designer, whether that's an architect, engineer, or design-build contractor.

Key Point: The 179D sunset doesn't close the door on retroactive claims. Buildings going back to 2006 may still produce large catch-up deductions through Form 3115 — no amended returns needed.

Could Section 179D Come Back?

The 179D sunset hasn't been ignored in Washington. 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. One of its key proposals is to bring Section 179D back as a permanent deduction with no end date.

The bill hasn't been signed into law yet, and today's rules still apply. But its introduction shows there's real interest on Capitol Hill in keeping energy-efficiency incentives alive for commercial construction — and that's worth watching, especially for developers and designers with projects still in planning.

Key Point: 179D isn't done yet. Retroactive claims are still on the table, and active legislative efforts suggest a permanent end isn't a sure thing.

What I'm Telling Clients Today

My approach to the One Big Beautiful Bill has stayed the same: know what's permanent, move quickly on what's time-sensitive, and don't assume your current advisor is finding everything. What I keep seeing — across hundreds of client conversations — is that most people think their CPA is optimizing their taxes when the CPA is really just handling compliance. Those are two very different jobs, and the gap between them is where real money slips away.

If your project broke ground before June 30, 2026, check your 179D eligibility and make sure your energy certification and documentation are in order. If you have older projects where 179D was never claimed, a lookback study can tell you whether a Form 3115 catch-up is still possible. And if you're keeping an eye on the Fitzpatrick bill or similar legislation, staying close to a knowledgeable advisor is the best way to move fast when the rules change.

Key Point: Compliance and strategy aren't the same job. The most expensive mistake I see isn't getting something wrong — it's not knowing what was available in the first place.

Key Takeaways

• 100% bonus depreciation is now permanent for qualified property placed in service after January 19, 2025 — this changes the planning math on nearly every commercial acquisition.

• Cost segregation studies are generating significantly stronger first-year returns under current rules, with typical ROI ranging from 4x to 6x the cost of the study.

• R&D expensing is restored for tax years beginning after December 31, 2024, and the R&D Tax Credit is now permanent — removing multi-year planning uncertainty for innovative businesses.

• The amended return deadline for eligible small businesses to recover capitalized R&D costs was July 4, 2026. If you missed it, talk to a specialist immediately.

• Section 179D has a hard sunset for projects where construction began after June 30, 2026 — but retroactive claims going back to 2006 remain available through IRS Form 3115.

• The American Energy Dominance Act, introduced in April 2026, proposes to restore 179D permanently. It hasn't passed, but it's worth monitoring.

• Compliance and tax strategy are not the same function. The gap between them is where the most significant opportunities tend to go uncaptured.

My team at Cash Flow Strategies, Inc. and I have been helping clients work through this kind of shifting environment for over 23 years. Whether you're looking at a recent purchase, reviewing years of unclaimed deductions, or trying to make sense of what the next round of legislative changes might mean for you, the starting point is always the same: a no-cost review that shows you what's still on the table.

Frequently Asked Questions

What is the One Big Beautiful Bill Act?
The One Big Beautiful Bill Act is a major tax law signed on July 4, 2025. Its key changes include making 100% bonus depreciation permanent, reversing the mandatory R&D amortization rules under Section 174, and setting a hard end date for the Section 179D energy-efficient building deduction.

Does 100% bonus depreciation apply to my property?
For most qualified property bought or newly built after January 19, 2025, yes. Property with a purchase or construction date on or before January 19, 2025 may still fall under the old phase-down rules. A cost segregation study can show you which assets qualify and how much you're able to deduct.

What is a cost segregation study and how does it work?
A cost segregation study is an engineering-based tax review that finds parts of a commercial building that qualify for shorter depreciation schedules — typically five, seven, or fifteen years instead of 27.5 or 39. When those parts qualify for 100% bonus depreciation, the first-year tax write-off can be very large. A typical study costs around $10,000 and often produces $40,000 to $60,000 in year-one tax savings on a $1 million property.

Can I still claim R&D tax credits for prior years?
Smaller businesses with average gross receipts under $31 million for 2022 through 2024 had a chance to amend past returns for meaningful refunds. That deadline was July 4, 2026. If you haven't looked into this yet, talk to a tax specialist as soon as possible to find out what options are still open.

Is Section 179D completely gone?
Not entirely. The deduction is still available for projects where construction started on or before June 30, 2026. Also, qualifying buildings built or renovated as far back as 2006 may be eligible for a retroactive claim through IRS Form 3115 — no amended returns needed. If you've never claimed 179D on a past project, it's worth checking whether something was missed.

What is Form 3115 and how does it relate to Section 179D?
Form 3115 is an IRS form used to request a change in accounting method. For Section 179D, it lets building owners claim a missed deduction as a catch-up adjustment on their current-year return — without filing amended returns for past years. The specific code used is Change Number 152.

What is the American Energy Dominance Act?
It's a bill introduced in April 2026 by Congressman Brian Fitzpatrick of Pennsylvania, with bipartisan support. It proposes to bring Section 179D back as a permanent deduction with no end date. The bill hasn't been signed into law, but it shows real interest in keeping energy-efficiency incentives alive for commercial construction.

What's the difference between tax compliance and tax strategy?
Tax compliance means filing accurately based on what already happened. Tax strategy means making decisions ahead of time to legally reduce your tax bill. Most CPAs handle compliance — they file correctly based on what you give them. Tax strategy means looking at what provisions apply to your situation before decisions get made. The gap between those two is where most unclaimed deductions live.