July 2026 Deadline: Cut R&D Credit Tax Burden with Section 280C
Key takeaways
• Eligible businesses with $31 million or less in average annual gross receipts for 2022–2024 have until July 6, 2026, to file amended returns making, or revoking, a Section 280C election.
• Without the 280C election, claiming the full R&D credit on an amended return triggers an "addback" that increases taxable income often creating cascading state and pass-through complications.
• The election trades a modestly reduced credit (approximately 79% of gross credit at a 21% tax rate) for elimination of the addback — a trade-off that is favorable for most businesses.
• This retroactive window, created by the One Big Beautiful Bill Act (OBBBA), is a one-time exception to normal rules. It expires July 6, 2026 or earlier if the statute of limitations has already closed for a given year.
• ADP has helped thousands of businesses identify, document and recover R&D tax credits. This article is for informational purposes only and does not constitute tax or legal advice. Consult a qualified tax advisor before filing amended returns.
If your business invested in research and development between 2022 and 2024, a rare and time-limited opportunity to reduce your tax burden is closing fast. Thanks to a narrow provision in the One Big Beautiful Bill Act (OBBBA), signed into law July 4, 2025, eligible businesses may amend prior-year returns to make, or revoke, a Section 280C election. That window closes July 6, 2026.
The stakes are real. ADP's tax credit specialists have seen business owners assume that claiming the R&D tax credit on an amended return is straightforward, only to discover an often-overlooked tax consequence called the "addback" that can partially offset the benefit, trigger pass-through income complications or require amendments to multiple state returns. The Section 280C election is specifically designed to eliminate that problem. Understanding how it works, and acting before the deadline, could mean a materially better outcome for your business.
The addback: the R&D credit complication most businesses miss
When a business claims the full R&D tax credit, Section 174 of the Internal Revenue Code requires reducing deductible expenses by the amount of the gross credit, the "addback." The result: taxable income rises by the same amount as the credit, which can partially cancel the benefit.
For C corporations, the income increase may generate additional federal and state corporate tax. For S corporations and partnerships, the most common structures among businesses in the eligible size range, the income increase flows through to individual owners' personal returns. Those owners may then owe additional state income taxes, often requiring amended personal returns in states that don't automatically conform to federal changes.
ADP's tax credit team regularly encounters this scenario: a business files an amended return to claim R&D credits, the addback triggers unexpected pass-through income, and the business owner is left with an unanticipated tax bill and a stack of state return amendments they hadn't planned for.
To understand the broader context behind these rules, ADP's SPARK blog has previously covered the five-year amortization rules introduced under the Tax Cuts and Jobs Act and IRS guidance updates on R&D credits that shaped today's landscape.
Section 280C election: the simpler, often smarter path
The Section 280C(c)(2) election eliminates the addback problem with a straightforward trade-off: accept a modestly reduced credit in exchange for keeping the full research and experimental (R&E) expense deduction intact.
At a 21% corporate tax rate, the election produces a credit equal to approximately 79% of the gross credit. For most businesses, the net federal tax effect is similar or identical to claiming the full credit with the addback, but the state complications, pass-through income adjustments and compliance complexity of the addback are eliminated entirely. The election is made on Form 6765, Credit for Increasing Research Activities, by checking “Yes” on Box 17 or 34 for tax years prior to 2024 or Item A for tax years 2024 and after.
Under normal rules, the 280C election can only be made on a timely filed original return, including extensions, and is irrevocable once made. Amended returns ordinarily cannot include a new or revised 280C election.
The OBBBA created a one-time exception. IRS Revenue Procedure 2025-28, issued Aug. 28, 2025, allows eligible small businesses to make a late 280C election, or revoke a prior one, on amended returns filed by July 6, 2026, or the earlier expiration of the statute of limitations for each open tax year. After that date, the exception ends and the original-return-only rule returns.
For a comprehensive overview of the OBBBA's impact on R&E expensing, see H.R. 1, The One Big Beautiful Bill Act, Enacted July 4, 2025 on ADP's SPARK blog.
Who qualifies and what the July 6, 2026, deadline means
The retroactive window is available to businesses with $31 million or less in average annual gross receipts for 2022, 2023 and 2024, as measured under the Section 448(c) gross receipts test. Gross receipts for this purpose include total sales (net of returns and allowances), services income, rents, royalties, dividends, interest and other amounts received.
Eligible businesses fall into two broad categories:
• Businesses that claimed R&D credits on original 2022–2024 returns and performed the addback, these may benefit from making the 280C election retroactively, simplifying state compliance and potentially recovering over-reduced deductions.
• Businesses that did not claim R&D credits on those returns and are now considering amended return filings, these should model whether claiming the credit with the 280C election produces a better outcome than claiming the full credit with the addback.
One critical complexity: controlled group aggregation rules apply. Businesses that are part of a parent-subsidiary group, brother-sister group or other common-control structure must aggregate gross receipts across all entities when determining eligibility. A business that appears to fall well under $31 million on its own may exceed the threshold when combined with affiliated entities. Failing to apply aggregation rules correctly can result in claiming elections the taxpayer was not entitled to, or, conversely, forfeiting a legitimate opportunity.
Important: The deadline is the earlier of July 6, 2026, or the expiration of the statute of limitations under Section 6511 for each open year. For a 2022 return filed March 15, 2023, the three-year statute may close as early as March 15, 2026 — well before the OBBBA's outer deadline. Businesses and their advisors should verify each year's statute of limitations status immediately.
What experience shows
ADP has helped thousands of businesses identify, document and recover R&D tax credits across industries ranging from manufacturing and software development to food science and engineering services. That experience across a broad client base gives ADP's tax credit specialists a practical view of where the 280C election delivers the most benefit, and where the analysis is more nuanced.
While C corporations will benefit from acting now, the businesses that benefit most are those with pass-through structures, S corporations and partnerships, where the addback creates the greatest downstream complexity. We've seen situations where owners assumed their amended return would be straightforward, only to discover that the addback triggered additional tax and/or state-level amended filings they hadn't anticipated. The 280C election, made retroactively within this window, can eliminate that entire chain of consequences.
Our scale also means familiarity with the aggregation rules that trip up many businesses evaluating their eligibility. The $31 million threshold looks simple, but for businesses with related entities, subsidiaries or common ownership structures, the analysis requires careful application of the Section 448(c) rules before any amended return is filed.
For context on the broader OBBBA legislation that created this window, including the permanent restoration of immediate R&E expensing under new Section 174A for tax years beginning after Dec. 31, 2024, see H.R. 1, The One Big Beautiful Bill Act, Enacted July 4, 2025 on ADP's SPARK blog.
Who should act — and act now
Decision-makers at businesses with $31 million or less in average gross receipts for 2022–2024, including CFOs, tax directors, controllers and CPAs serving these clients should evaluate this opportunity without delay. The binding constraint is time: once July 6, 2026, passes (or the statute of limitations closes for a given year), the flexibility to make or revoke the 280C election on an amended return is gone permanently.
The core questions to evaluate:
• Did we claim R&D credits on 2022, 2023 or 2024 original returns and perform the addback? If yes, model whether the retroactive 280C election reduces net tax costs and simplifies state compliance.
• Did we perform R&D activities in those years but not claim credits? If yes, evaluate whether an amended return claiming the credit with the 280C election produces a net benefit before statute of limitations deadlines close.
• Are we subject to controlled group aggregation? If yes, confirm eligibility before filing.
For businesses seeking expert guidance on whether amended returns and the 280C election make sense for their specific situation, ADP SmartCompliance® Tax Credits provides the expertise to evaluate options and act within this limited window.
This article is for informational purposes only and does not constitute tax or legal advice. Consult a qualified tax advisor before filing amended returns.
Frequently asked questions (FAQs)
1. What is the Section 280C election, and how does it affect R&D tax credit claims?
The Section 280C(c)(2) election allows a taxpayer to claim a reduced R&D tax credit — typically approximately 79% of the gross credit at a 21% corporate tax rate — in exchange for keeping the full research and experimental (R&E) expense deduction without performing an addback. Without this election, a taxpayer claiming the full credit must reduce its deductions by the amount of the gross credit, increasing taxable income. This income increase can create complications for shareholders or partners in pass-through entities and may require amendments to multiple state income tax returns. The election is made on Form 6765, Credit for Increasing Research Activities, by checking “Yes” on Box 17 or 34 for tax years prior to 2024 or Item A for tax years 2024 and after. It is irrevocable for the tax year in which it is made, except within the special retroactive window created by the OBBBA through July 6, 2026. For most businesses operating at the 21% corporate rate, the net federal tax outcome under the two approaches is similar, making the 280C election an attractive compliance simplifier.
2. Who qualifies for the retroactive Section 280C election under the OBBBA, and what is the July 6, 2026 deadline?
Eligible taxpayers are those with $31 million or less in average annual gross receipts for the three-year period covering 2022, 2023 and 2024, as measured under the Section 448(c) gross receipts test (which includes gross sales, rents, royalties, dividends, interest and other income). Businesses that meet this threshold may file amended returns, or amended administrative adjustment requests (AARs) in the case of partnerships for tax years beginning after Dec. 31, 2021, and before Jan. 1, 2025, to make a late 280C election, revoke a prior 280C election, or claim the R&D credit in coordination with retroactive Section 174A expensing. The deadline is the earlier of July 6, 2026, or the expiration of the statute of limitations under Section 6511 for each open tax year. Revenue Procedure 2025-28, issued Aug. 28, 2025, provides specific procedures for making these elections on amended returns. Businesses and their CPA advisors should confirm each year's statute of limitations status early, as some years may close before July 6, 2026.
3. What is the "addback" in the context of the R&D tax credit, and why does it matter for S corporations and partnerships?
The addback is the requirement under Section 174 (as modified by the Tax Cuts and Jobs Act and now the OBBBA) that when a taxpayer claims the full, unreduced R&D tax credit, it must reduce its deductible expenses by the amount of the gross credit claimed. This reduction in deductions effectively increases taxable income by the same amount. For C corporations, this income increase may result in additional federal and state corporate tax, partially or fully offsetting the value of the credit. For S corporations and partnerships, which are common structures among businesses in the eligible size range, the income increase flows through to individual shareholders or partners, who may then owe additional federal and state income taxes on their personal returns, necessitating amended personal income tax returns in many states. This cascade effect can be administratively burdensome and financially costly in states that don't automatically conform to federal amendments. The 280C election eliminates the addback entirely by accepting a modestly reduced credit, which is why it is generally viewed as taxpayer-friendly in most circumstances.
4. What happens after July 6, 2026? Can businesses still claim the R&D credit or make 280C elections?
After July 6, 2026, the standard rules governing the Section 280C election resume in full force. Under those rules, the election can only be made on a timely filed original return, including extensions, not on an amended return. This means a business that missed the retroactive window will not be able to amend 2022, 2023 or 2024 returns to add or modify a 280C election. Amended returns for those years may still be filed to claim or adjust the R&D credit itself, but the taxpayer would then be subject to the addback without the election's protection. For tax years beginning after Dec. 31, 2024, the standard rules apply from the outset: taxpayers may make the 280C election on their originally filed returns. Additionally, for larger businesses that do not qualify for the retroactive election window, some planning opportunities exist to address unamortized 2022–2024 R&E costs through accounting method changes under Rev. Proc. 2025-23 and 2025-28, though those avenues do not provide the same 280C flexibility as the retroactive election window. The July 6, 2026, deadline is effectively final and non-extendable for retroactive 280C elections under the OBBBA.
5. How do small businesses confirm they meet the $31 million gross receipts threshold, and are there aggregation rules to consider?
The $31 million average gross receipts threshold is determined under the Section 448(c) test, which measures average annual gross receipts over the three preceding taxable years, in this case, 2022, 2023 and 2024. Gross receipts include total sales (net of returns and allowances), income from services, rents, royalties, dividends, interest and any other amounts received. One critical complexity is that controlled group aggregation rules apply: businesses that are part of a parent-subsidiary group, brother-sister group or other common-control structure must aggregate gross receipts across all entities when determining eligibility. A business that appears to fall well under $31 million on its own may exceed the threshold when combined with affiliated entities under common control. Failing to apply aggregation rules correctly can result in claiming elections the taxpayer was not entitled to, potentially triggering penalties under Section 6662 for substantial understatement of tax. Conversely, incorrectly concluding that aggregated receipts exceed $31 million when they don't could result in the taxpayer forfeiting a legitimate opportunity. Given the technical nature of this analysis, consultation with a qualified tax advisor is strongly recommended before filing amended returns under this provision.
6. What does the OBBBA's overhaul of Section 174 mean for R&D expensing going forward?
The OBBBA permanently restores immediate expensing of domestic research and experimental (R&E) costs through new Section 174A for tax years beginning after Dec. 31, 2024. This ends the five-year amortization requirement that the Tax Cuts and Jobs Act imposed beginning in 2022, a rule that created significant complexity for businesses claiming R&D credits. For the retroactive window eligible businesses, who meet the $31 million and under gross receipts threshold, may also amend 2022–2024 returns to take advantage of retroactive Section 174A expensing in coordination with the 280C election. The interaction of these provisions, immediate expensing, the R&D credit and the 280C election, requires careful modeling for each tax year.
For a comprehensive overview of the OBBBA's impact on R&E expensing, see H.R. 1, The One Big Beautiful Bill Act, Enacted July 4, 2025 on ADP's SPARK blog.
This article is for informational purposes only and does not constitute tax or legal advice. Laws and regulations may change. Consult a qualified tax advisor to evaluate your specific circumstances before filing amended returns.
