Section 174 R&D Capitalization: The Complete 2026 Guide for Founders and Finance Teams

If you run a company that writes software, designs hardware, formulates products, or conducts research of any kind, Section 174 is one of the most important pages of the tax code you will ever touch. For the past three tax years, it has also been one of the most painful. Startups with real operating losses were handed surprise tax bills. CFOs scrambled to amend returns. Engineering payroll became a tax planning exercise.

Here is the good news: the rules changed again in 2025, and most domestic research spending can now be expensed immediately. But the fine print matters. If you spent money on R&D between 2022 and 2024, there is money on the table you may be able to reclaim — and a hard deadline for doing it.

This guide walks through what Section 174 is, how it has evolved, what the current rules look like for 2025 and 2026, and what you should be doing right now if your company spends money on research or product development.

What Section 174 Actually Covers

Section 174 of the Internal Revenue Code governs how businesses treat "research or experimental expenditures" — a surprisingly broad category that goes well beyond white-coat laboratories. The IRS and regulations have long treated the following as Section 174 expenses:

• Software development costs, including salaries of software engineers
• Product design and prototyping costs
• Testing and quality improvement activities
• Formulation work in chemistry, pharma, and consumer packaged goods
• Engineering salaries and contractor costs tied to developing new or improved products or processes
• Cloud computing and supplies consumed in research
• Patent-related legal and filing fees in some cases

If your team is working on something new, improved, or technically uncertain, the chances are high that those costs fall under Section 174. Software development in particular is explicitly covered — which is why this rule has such an outsized effect on tech companies.

Note that Section 174 is different from the Section 41 R&D tax credit, which is a dollar-for-dollar credit against tax owed. The two rules interact, but they are not the same thing. Section 174 determines when you can deduct R&D expenses. Section 41 determines whether you get an additional credit on top.

A Brief History: Why Everyone Panicked in 2022

Before 2022, companies could deduct 100% of R&D expenses in the year they were paid. A startup spending $2 million on engineering salaries reduced its taxable income by $2 million. Simple.

The Tax Cuts and Jobs Act of 2017 contained a delayed time bomb: starting in tax years beginning after December 31, 2021, companies had to capitalize and amortize their Section 174 expenses instead.

The amortization schedule was brutal:

• Domestic R&D: 5-year amortization, with a half-year convention (meaning only 10% of Year 1 spend was deductible)
• Foreign R&D: 15-year amortization, with a half-year convention (only 3.33% deductible in Year 1)

Suddenly a cash-losing startup could owe real tax. That $2 million in engineering salaries generated only $200,000 in deductions in Year 1. Companies that broke even on cash flow found themselves with "paper profits" of $1.8 million and tax bills they could not afford.

Every founder, tax adviser, and small business CFO spent three years begging Congress to fix it.

What Changed in 2025: The One Big Beautiful Bill Act

In 2025, Congress passed the One Big Beautiful Bill Act (OBBBA), which created new Section 174A and effectively restored immediate expensing for domestic R&D. The key changes took effect for tax years beginning after December 31, 2024.

The New Rules at a Glance

Domestic R&D (Section 174A):

• Full immediate expensing is back for costs paid or incurred in tax years starting after December 31, 2024
• This is permanent, not a temporary fix
• Taxpayers can alternatively elect to capitalize and amortize over a minimum of 60 months if that is more advantageous for their situation

Foreign R&D:

• Still must be capitalized
• Still amortized over 15 years
• Half-year convention still applies

So the discrimination between domestic and foreign research is now baked into the permanent code. If you are choosing between hiring a U.S.-based engineer and a contractor overseas, the tax treatment will materially affect the economics.

Recovery of 2022–2024 Amortized Costs

If your company was forced to capitalize R&D expenses between 2022 and 2024, you likely have a large pool of unamortized costs sitting on the books. OBBBA provides two paths to recover these faster:

1. Deduct remaining unamortized balance over one or two years starting with the first tax year beginning after December 31, 2024, or
2. Small business retroactive election: qualifying small businesses can amend their 2022, 2023, and 2024 returns to apply immediate expensing retroactively.

The Small Business Deadline You Cannot Miss

Here is the urgent part. Small business taxpayers — defined as having average annual gross receipts of $31 million or less over the 2022–2024 period — can elect to retroactively expense their domestic R&D costs back to 2022. This unlocks refunds that can be substantial, especially for loss-making startups that were never profitable but still owed tax under the old rules.

The deadline to file the amended returns is July 6, 2026, or the normal statute of limitations for the return, whichever is earlier.

If you qualify, this is real money. Start the conversation with your accountant now, not in June.

Who Qualifies as a "Small Business" for the Lookback?

The $31 million gross receipts test uses the three-year average rule familiar from other parts of the tax code. Specifically, a company qualifies if average annual gross receipts for the three tax years preceding the year of the election do not exceed roughly $31 million, adjusted for inflation.

Some nuances that catch people out:

• Aggregation rules apply. Commonly-controlled groups have to combine their receipts. A holding company with several subsidiaries may blow past the threshold in aggregate even if no single entity does.
• Gross receipts include everything. This is not just revenue — it includes interest, dividends, and other income.
• Short tax years are annualized for the calculation.

If you are near the threshold, do not eyeball it. Run the numbers with your tax adviser.

Practical Mechanics: How the Expensing Election Works

Starting in 2025, you get a choice each tax year:

Option A: Immediate expensing of domestic R&D. The default treatment under new Section 174A. Deduct 100% in the year paid or incurred.

Option B: Capitalize and amortize over at least 60 months. Some companies may want to smooth deductions to match revenue patterns or preserve net operating loss carryforwards for later years when they expect higher taxable income.

The election is made on a timely filed return (including extensions). Once made, the election generally applies going forward and changing methods typically requires IRS approval through Form 3115 (Application for Change in Accounting Method).

For foreign R&D, there is no choice. Capitalize and amortize over 15 years. Full stop.

Coordination with the R&D Tax Credit (Section 41)

If you claim the Section 41 R&D credit, there is a coordination rule you need to know. For tax years beginning after December 31, 2024, you must either:

1. Reduce your domestic R&E expenditures by the amount of the gross research credit, or
2. Elect the reduced research credit under Section 280C(c) on a timely filed return.

In plain English, the IRS does not let you deduct the expense and claim the full credit on the same dollar. You pick one benefit in full, or you take a reduced version of each. Most small businesses elect the reduced credit because it keeps the math simpler and the deductions larger.

This is also why the R&D credit tends to be far more valuable than the deduction alone for pre-profit startups — a credit offsets tax dollar-for-dollar, while a deduction only saves you cash at your marginal rate.

Form 6765: New Reporting Is Coming

Claiming the R&D credit now involves significantly more disclosure than it used to. The IRS revamped Form 6765 to include a new Section G, which asks for detailed information about:

• Business components giving rise to qualified research
• The type of research activity
• Amounts allocated to each business component
• Officer compensation and wages

Section G is optional for tax year 2025 but mandatory for most taxpayers starting with tax year 2026. If you plan to claim the credit, start collecting this information at the project level now. Retrofitting it after the fact is painful and often produces weaker documentation.

Documentation: The Part Most Companies Get Wrong

Regardless of whether you expense immediately or amortize, whether you claim the credit or not, the audit risk on R&D expenditures is elevated. The IRS is deploying AI tools to select returns for examination, and R&D is an area that historically produces favorable adjustments for the government.

Strong documentation looks like:

• Project-level tracking of who worked on what and for how long
• Contemporaneous notes on the technical uncertainties being resolved
• Time tracking or allocation data for engineers and scientists splitting time across projects
• Clear separation between qualified research and ordinary business operations (maintenance, marketing, administrative work)
• Invoices and contracts that describe the research scope in sufficient detail
• Version control history for software projects, tied to tax-year expenditures

The companies that survive audits cleanly are the ones that treat R&D documentation as a process, not an annual panic.

Common Mistakes to Avoid

1. Treating all engineering payroll as R&D. Not every engineer is doing qualifying research. A backend engineer keeping the lights on is probably doing operations, not Section 174 work. Be rigorous about the split.

2. Ignoring the foreign vs. domestic distinction. With 15-year amortization baked into the permanent law, offshore contractor spend has a real tax cost. Model it.

3. Missing the July 6, 2026 deadline. If you qualify for the small business lookback, the clock is running. Amended returns take time to prepare and file correctly.

4. Double-counting across the credit and the deduction. You cannot take both in full. Make the Section 280C(c) election or reduce expenditures by the credit.

5. Retrofitting documentation at year end. Build the habit into your project management tooling. Tag time entries, link invoices to projects, and keep technical uncertainty notes in your engineering docs.

6. Forgetting about state taxes. Not every state conforms to the federal Section 174A rules. Some states still require capitalization. Check your state's specific treatment or you may over-deduct on state returns.

Example: How This Plays Out for a Typical Startup

Imagine a 25-person SaaS company with $4 million of annual revenue and $6 million of qualified domestic R&D spend (mostly engineering payroll).

Under the 2022–2024 rules: Only $600,000 (half of 20%) of the $6 million was deductible in Year 1. The company showed $5.4 million of "paper profits" on an operational loss, creating taxable income of perhaps $3 million and a federal tax bill of $630,000. For a company burning cash, this was existential.

Under the 2025+ rules: The full $6 million is deductible in Year 1. Taxable income is appropriately negative, the company creates a net operating loss it can carry forward, and cash stays in the business.

The retroactive lookback bonus: If this company had similar spending in 2022 and 2023 and qualifies as a small business, amending those returns could produce a meaningful refund — often hundreds of thousands of dollars — to be received in 2026.

This is why the R&D community has treated the OBBBA change as the single most important tax development of the decade for innovative small businesses.

How to Think About R&D Tax Strategy Going Forward

With the permanent restoration of domestic expensing, the tax strategy conversation shifts. Instead of fighting for cash preservation under a punitive capitalization regime, founders and CFOs can return to more strategic questions:

• Where should we hire? The domestic-vs-foreign tax split is now permanent, so the cost of offshore talent includes a tax drag.
• Which projects qualify for the R&D credit? The credit is still the most valuable tool in the R&D tax toolbox for pre-profit companies.
• How do we document R&D systematically? With Form 6765 Section G mandatory in 2026, process discipline matters.
• Is immediate expensing always better? Usually, yes. But companies expecting large future taxable income may prefer to capitalize and match deductions with future profits.

A short conversation with a tax professional who specializes in R&D can be worth many multiples of the fee, particularly if you have unamortized 174 balances from 2022–2024 or substantial ongoing research spend.

Keep Your R&D Records Audit-Ready

The foundation of every successful R&D tax strategy is clean, contemporaneous financial data. Whether you are tracking engineering time by project, tagging invoices to research activities, or preparing for a Form 6765 Section G disclosure, you need an accounting system that gives you transparency and auditability all the way down to the transaction level.

Beancount.io offers plain-text, version-controlled accounting that is transparent, AI-ready, and built for the kind of detailed expense tagging that R&D tax work demands. No black boxes, no vendor lock-in, and every dollar traceable. Get started for free and give your tax team the clean data they need — whether for the July 6, 2026 lookback deadline or for the tax years ahead.