§174 R&D Expensing Restored: §174A and the OBBBA Retroactive Fix

How TCJA broke R&D treatment

From 1954 through 2021, businesses could deduct research and experimental (R&E) expenditures in the year incurred under former §174: software developers, R&D-intensive startups, and manufacturers treated salaries, contractor fees, cloud costs, and supplies as ordinary expenses. TCJA's revenue-offset provision (effective for tax years beginning after 12/31/2021) eliminated immediate expensing and required: • Domestic R&E → 5-year straight-line amortization • Foreign R&E → 15-year straight-line amortization • Half-year convention in year of acquisition (so 10% in year 1, 20% in years 2–5, 10% in year 6) For a cash-strapped startup spending $2M on engineering salaries, the change meant deducting $200,000 instead of $2,000,000 in year 1: creating phantom income, tax bills with no cash to pay them, and forcing layoffs. The provision drew bipartisan condemnation almost immediately and was the single most-lobbied tax-fix item from 2022 through 2025.

OBBBA §174A: immediate expensing restored

OBBBA enacted new IRC §174A effective for tax years beginning after 12/31/2024: • Domestic R&E: fully deductible in the year paid or incurred (back to the pre-TCJA treatment) • Foreign R&E: remains on the 15-year amortization schedule, political compromise that preserves some of the original revenue offset 'Domestic' means R&E performed in the United States (and territories). Where the costs are paid TO is irrelevant; where the work is performed governs. For software development specifically, the legislation clarifies that software-development costs incurred in the US qualify for §174A immediate expensing, settling years of post-TCJA ambiguity.

The retroactive small-business window

For taxpayers with average annual gross receipts of $31 million or less (the §448(c) small-business threshold) for the prior 3 years, OBBBA provides retroactive relief covering the broken 2022, 2023, and 2024 tax years. Two paths: **Path 1: Amended returns**: File amended 2022, 2023, and 2024 returns claiming full expensing under the restored treatment. Recover overpaid tax via refund. **Path 2: Accelerated catch-up on 2025 or 2026 return**: Elect to deduct ALL remaining unamortized 2022–2024 domestic R&E on the 2025 return, OR spread over 2025 and 2026. Avoids amended-return administrative burden. Larger businesses (>$31M avg gross receipts) do NOT get retroactive relief. They continue amortizing 2022–2024 R&E over the original 5-year schedule, but get the immediate-expensing treatment going forward for 2025+ costs.

Interaction with the §41 R&D Credit

The §41 Research Credit is separate from §174 deduction treatment. Both are available simultaneously, but coordinated under IRC §280C(c)(2): • By default, claiming the §41 credit reduces the §174 / §174A deduction dollar-for-dollar by the credit amount • Alternatively, the taxpayer may elect under §280C(c)(2) for a 'reduced credit' (credit × (1 − maximum federal corporate rate, currently 21%) = credit × 0.79) and keep the full deduction The reduced-credit election usually benefits taxpayers in the 21% federal corporate bracket or those with state credit coordination concerns. Always model both paths for the specific year.

Your state may not follow any of this

Everything above is federal. A state that decouples can take the whole benefit away, and at least one large one has. **New York has decoupled from the federal treatment of research and experimental expenditures** for tax years beginning on or after 1 January 2025, under the 2026-2027 State Budget, along with §168(n) accelerated depreciation on qualified production property. The full federal deduction is added back and a recomputed subtraction allowed. So the §174A restoration this guide is about is worth nothing on a New York return, and a reader who plans from the federal rules alone will be wrong. State treatment of §174 is not something to infer from whether a state uses rolling or fixed-date conformity. Illinois is a rolling conformity state and still decouples from bonus depreciation, which is the same trap in a different provision. Check the state page for each state you file in before relying on a federal figure.

Documentation that survives §41 audit

Both §174A and §41 require documenting that costs meet the qualified research definition: experimentation, technological in nature, intended to discover information that eliminates uncertainty, and resulting in a new or improved business component. Project-level documentation should include: • Nature of uncertainty being resolved • Process of experimentation followed • Technological nature of the research • Time-tracked allocation of employee/contractor hours to qualifying projects IRS Audit Technique Guide for Research Credit Claims (2023 update) sets out the substantiation standards. Routine software maintenance, UI redesign, or post-deployment debugging generally does NOT qualify.

Statute references

• Restored domestic R&E immediate expensing — IRC §174A (added by OBBBA)
• TCJA capitalization rule (still applies to foreign R&E) — IRC §174
• Research credit — IRC §41
• Reduced-credit election — IRC §280C(c)(2)
• Small-business gross-receipts threshold — IRC §448(c) ($31M for 2026)