The R&D tax credit is a federal credit under IRC Sec. 41 for developing or improving products, software, processes, or techniques in the United States. For a profitable company it reduces income tax. For one that owes little or none, a qualified small business can instead apply part of it against employer payroll taxes.
That election is capped at $500,000 per year and limited to five tax years. The second limit is the one most write-ups leave out. Here is how the credit works, who is gated out, how much a venture-backed startup can realistically claim, and what the 2025 law changed.
The payroll tax offset, and the two limits on it
Under Sec. 41(h), a qualified small business can elect to apply the credit against the employer share of payroll taxes rather than income tax. The cap is $250,000, increased by a further $250,000 for tax years beginning after December 31, 2022, so $500,000 per year (Sec. 41(h)(4)(B)(i)).
The second limit gets missed. Sec. 41(h)(4)(B)(ii) blocks the election entirely if the taxpayer has made it for five or more preceding tax years. The payroll tax offset is a five-year runway, not a permanent feature.
Who qualifies, and who does not
Sec. 41(h)(3) defines a qualified small business narrowly. Both tests must be met:
- Gross receipts of less than $5,000,000 for the tax year (Sec. 41(h)(3)(A)(i)(I)), measured under Sec. 448(c)(3).
- No gross receipts for any tax year preceding the 5-tax-year period ending with that year (Sec. 41(h)(3)(A)(i)(II)).
The exclusions matter as much as the tests:
- Organizations exempt from tax under Sec. 501 are excluded outright (Sec. 41(h)(3)(B)).
- Any gross receipts further back than the five-year window fails the second test permanently, however small the company is now. Age of revenue, not size, is the binding constraint.
- A taxpayer that has already made the election for five or more preceding tax years cannot make it again (Sec. 41(h)(4)(B)(ii)).
- Entities aggregated under Sec. 41(f)(1) count as a single taxpayer (Sec. 41(h)(5)(A)), so a controlled group cannot multiply the cap.
- Research outside the United States, Puerto Rico, or a US possession is not qualified research at all (Sec. 41(d)(4)(F)).
The election must be made on or before the due date, including extensions, of the originally filed return for the tax year (Sec. 41(h)(4)(A)(ii); the Instructions for Form 6765 say the same). A return amended after that date cannot make it, so a missed election is generally not recoverable.
How the offset reaches payroll
The credit is computed on Form 6765 and attached to the income tax return; the offset is claimed on Form 8974 with the employment tax return. Under Sec. 3111(f), it applies against the employer share of Social Security tax for the first calendar quarter beginning after that return is filed, and any excess against the employer share of Medicare tax. Filing starts the clock, so cash lags.
What counts as qualified research
Sec. 41(d) sets a four-part test, applied per business component. All four must be met:
- Qualified expenditure: eligible for treatment as a domestic research or experimental expenditure under Sec. 174A (Sec. 41(d)(1)(A)).
- Technological in nature: undertaken to discover information that fundamentally relies on the physical or biological sciences, engineering, or computer science (Sec. 41(d)(1)(B)(i)).
- Business component purpose: that information must be intended to be useful in developing a new or improved business component (Sec. 41(d)(1)(B)(ii)), meaning function, performance, reliability, or quality (Sec. 41(d)(3)).
- Process of experimentation: substantially all activities must be elements of a process of experimentation for a qualified purpose (Sec. 41(d)(1)(C)).
Sec. 41(d)(4) then carves activities back out: research after commercial production begins, adaptation to a customer's requirement, duplication, surveys, the social sciences, funded research, and research outside the United States. Internal-use software carries extra requirements. Qualified expenses (Sec. 41(b)) are mainly in-house wages for performing, directly supervising, or directly supporting research, plus supplies and contract research.
How much can you claim?
Under the Alternative Simplified Credit, the credit is 14% of qualified research expenses above 50% of your prior three-year average. If you had no qualified research expenses in any one of the three preceding tax years, it is instead 6% of current-year expenses (IRC Sec. 41(c)(4)(B)). That covers any company in its first three tax years, unless it belongs to a controlled group with earlier research spend. It does not cover every first claim: a company claiming for the first time after three years of R&D uses the 14% formula. A realistic rule of thumb is roughly 6 to 10% of qualified research spend, landing at 6% when one of the three preceding years had none.
For a funded startup with an engineering team, that is frequently tens of thousands of dollars a year. Two things move the number more than the rate does: which activities survive the Sec. 41(d)(4) exclusions, and how much of each engineer's wages is genuinely attributable to qualifying work. A claim built from an undifferentiated payroll export tends to overstate both. To put your own numbers against it, use the R&D tax credit calculator.
How to claim it, step by step
- Compute the credit on Form 6765 and file it with your income tax return, electing the payroll offset. It must be a timely filed original return including extensions, never an amended one.
- File Form 8974 with your quarterly Form 941 payroll return. This is where the cash actually reaches you, so the benefit lags the election by a quarter or more.
- Keep documentation of qualifying activities and wages per business component. This is the part software helps with. See R&D tax credit software for startups.
The timing is worth planning around. Because the offset applies against payroll tax for the quarter beginning after the income tax return is filed, filing later means waiting longer for cash, and a company with nobody on payroll has no liability to offset at all.
The credit and the deduction do not stack
This is the most common error in R&D credit explainers, and it favours the taxpayer, which is why it survives. Sec. 280C(c)(1) reduces the domestic research or experimental expenditures otherwise deducted or charged to capital account by the amount of the credit allowed under Sec. 41(a). You do not get the full deduction and the full credit on the same dollars. The alternative is the Sec. 280C(c)(2) election: a reduced credit, computed by reference to the maximum corporate rate under Sec. 11(b), with the full deduction kept. It is irrevocable, made on the return by the filing deadline including extensions, and reported at Item A of Form 6765.
What the 2025 law changed, and what it did not
The One Big Beautiful Bill Act (P.L. 119-21) was signed on July 4, 2025. Section 70302(a) added IRC Section 174A: a full deduction for domestic research or experimental expenditures in the year paid or incurred, or an election under Sec. 174A(c) to amortize over not less than 60 months. It applies to tax years beginning after December 31, 2024, reversing prospectively the capitalization regime that had applied since tax years beginning after December 31, 2021.
Foreign research did not get the same treatment, and in one respect got worse. Under Sec. 174(a), it must still be capitalized and amortized over 15 years. Sec. 174(d), as amended, now denies any deduction or reduction to amount realized when the related property is disposed of, retired, or abandoned during that period; amortization simply continues. That applies to property disposed of, retired, or abandoned after May 12, 2025 (P.L. 119-21 Sec. 70302(b)(1)(C)(ii)).
What OBBBA did not do is newly restrict foreign research for the credit. Sec. 70302 updated the cross-reference in Sec. 41(d)(1)(A) from Sec. 174 to Sec. 174A, but that is conforming only: research outside the United States was already ineligible under Sec. 41(d)(4)(F). Advice to move engineering onshore because of a 2025 credit change rests on a misreading. OBBBA did not amend Sec. 41(h), so the $500,000 cap and the five-year limit stand.
| Credit (Sec. 41) | Domestic R&E (Sec. 174A) | Foreign R&E (Sec. 174) | |
|---|---|---|---|
| What it does | Reduces tax dollar for dollar | Sets when you deduct | Sets when you deduct |
| Treatment | Income tax credit, or payroll offset if the Sec. 41(h) gates are met | Full deduction, or elect 60+ month amortization | Capitalize, amortize 15 years, no recovery on disposition after May 12, 2025 |
| Effective | Unchanged by OBBBA | Tax years beginning after Dec 31, 2024 | Tax years beginning after Dec 31, 2024 |
| Reported on | Form 6765, plus Form 8974 for the offset | Income tax return | Income tax return |
| Interaction | Reduces the Sec. 174A deduction under Sec. 280C(c)(1) unless the (c)(2) election is made | Reduced by the Sec. 41(a) credit | Not eligible for the credit (Sec. 41(d)(4)(F)) |
OBBBA Sec. 70302(f) also let small businesses meeting the Sec. 448(c) gross receipts test elect retroactive application of Sec. 174A back to tax years beginning after December 31, 2021. Rev. Proc. 2025-28 set the deadline at one year after enactment, July 4, 2026, which fell on a Saturday and moved to July 6, 2026. That date has passed, and it was only half the test: Rev. Proc. 2025-28 confirms OBBBA did not modify the Sec. 6511 refund statute, so the operative deadline was the earlier of the two.
Treasury's 2025-2026 Priority Guidance Plan, released September 30, 2025, carries "Guidance under Sections 174, 174A, and related provisions of the Code regarding research and experimental expenditures and related issues" at item 8 and marks it published as Rev. Proc. 2025-28. That guidance is procedural — elections, method changes and amended returns — and does not settle the substantive questions, so positions taken now on unsettled points may need revisiting.
Questions to bring to your own accountant
These are the questions that tend to decide the answer, worth raising early rather than at filing:
- Do we clear both Sec. 41(h)(3) gates, and when exactly was our first dollar of gross receipts, counting interest and other income under Sec. 448(c)(3)?
- How many prior tax years have we already made the Sec. 41(h) election for, and how many of the five remain?
- Are we in a controlled group, and how do the Sec. 41(f)(1) aggregation rules affect our cap?
- Are we better off with the Sec. 280C(c)(2) reduced credit, or the full credit with a reduced deduction, at our rate?
- Which activities survive the Sec. 41(d)(4) exclusions, particularly internal-use software and work performed abroad?
- For 2025 forward, do we deduct under Sec. 174A(a) or elect to amortize under Sec. 174A(c), and what does each do to the credit?
- Do we have foreign R&E exposed to the Sec. 174(d) disposition rule, and does anything remain open on prior years under Sec. 6511?
The calculation is rarely the hard part. Wage allocation, business component detail, and contemporaneous documentation are what a Sec. 41 position stands or falls on under examination. If you want the data in shape before taking these questions to a preparer, that is what our tax team does, and R&D tax credit capture is part of the same engagement.
This article is educational and general. It is not tax, legal, or accounting advice, and creates no client relationship. Tax law changes and applies differently to different facts, and the Sec. 174 and Sec. 174A guidance issued so far is procedural, leaving substantive questions open as of publication. Do not take a position on a return based on this page. Consult a qualified tax professional about your own circumstances first.