R&D Expensing Is Back. The Retroactive Refund Window Has Closed.

For four years, one of the more damaging provisions in the tax code required businesses to capitalize research and experimental costs and deduct them over five years rather than immediately.

The effect fell hardest on companies that spend heavily on development and don't have large profits to absorb the hit. Software companies, engineering firms, product developers, and manufacturers doing process improvement found themselves paying tax on income they had already spent. A business that broke even on paper could owe substantial tax, because a large portion of its costs weren't deductible in the year incurred.

That requirement is gone. The One Big Beautiful Bill Act permanently restored immediate expensing for domestic research and experimental expenditures, for tax years beginning after December 31, 2024.

Foreign research remains subject to the fifteen-year amortization requirement. The restoration applies to domestic research only.

The retroactive window and where it stands

The law included a provision allowing eligible small businesses — generally those with average annual gross receipts under approximately $31 million for the 2022 through 2024 tax years — to apply the change retroactively by amending prior-year returns. For businesses that had capitalized substantial research costs in 2022, 2023, and 2024, those amendments could produce meaningful refunds.

That window closed on July 6, 2026 — one year from the law's enactment, moved off the July 4 weekend — and earlier than that for any year whose ordinary refund statute ran out first.

If your business filed those amendments, good. If it didn't, the retroactive path via amended return is no longer available.

What is still available

Several things remain, and they're worth checking.

Current-year expensing. Research costs incurred in 2025 and forward are immediately deductible. If your 2025 return hasn't been filed yet — many businesses are on extension until October — the treatment of research costs on that return matters and should be handled correctly the first time.

Remaining capitalized balances. Businesses that capitalized research costs in 2022 through 2024 and did not amend generally have unamortized balances still sitting on their books. The law provides mechanisms for accelerating the deduction of those remaining amounts, typically over a short period rather than the original schedule. This is an accounting method question and it does not depend on the amended return deadline. If you have capitalized R&D on your balance sheet, ask about this.

The research credit. Section 41's research credit is a separate provision from the Section 174 deduction rules and continues to be available. The two interact — there are coordination rules governing the deduction when the credit is claimed — but the credit itself was not the thing that changed.

What actually counts as research

This is where most businesses get it wrong, in both directions.

The definition is broader than laboratories and patents. Software development, including internal-use software under specific rules, generally qualifies. So does developing or improving a product, process, formula, technique, or invention. Engineering and design work aimed at resolving technical uncertainty typically qualifies. A manufacturer improving a production process is often doing qualifying research without calling it that.

It is also narrower than some businesses assume. Routine data collection, market research, quality control testing, adaptation of an existing product for a particular customer, and general management studies do not qualify.

The line generally turns on technical uncertainty — whether, at the outset, the business was uncertain about capability, method, or design and undertook a process of experimentation to resolve it.

Documentation is the recurring weak point

Whether you're claiming current deductions or the research credit, the substantiation requirements are real. What the IRS looks for is contemporaneous evidence: project records, time tracking that ties employee hours to specific development activities, documentation of the technical uncertainty being addressed, and records of the experimentation process.

Reconstructing this after the fact is difficult and considerably less persuasive. Businesses that build the tracking into their normal project management are in a far better position than those assembling it during an examination.

This article is general information, not tax advice for your specific situation. Qualification for research treatment is highly fact-dependent. Please talk with us before acting on anything here.