Section 174A changed R&D expensing. Your evidence still has to connect.

The federal tax treatment of domestic research changed substantially in 2025. That creates a useful reason to revisit the engineering cost ledger. It does not turn every software invoice into a tax credit, or remove the need to understand where work happened and what the company actually paid for.

For a finance leader, the practical task is to connect three things: current development spending, the remaining balance from earlier years, and the treatment actually reflected in filed returns. A spreadsheet containing only this year's salaries cannot answer all three.

This article covers U.S. federal rules researched on October 7, 2026. Its examples are illustrative planning exercises; elections and return positions need review against the company's facts.

What changed, and when

Public Law 119-21, enacted July 4, 2025, added Section 174A. It allows deductions for domestic research or experimental expenditures paid or incurred in tax years beginning after December 31, 2024. Software development is expressly included in the provision. A taxpayer may instead elect amortization over at least 60 months, beginning when benefits are first realized. Foreign research remains under Section 174 with 15-year amortization. These are enacted federal rules, not a pending proposal. Public Law 119-21, Section 70302.

The start of the tax year matters. A fiscal year beginning in 2024 and ending in 2025 should not be treated as though it began in 2025 simply because its return was prepared later. Put actual period dates in the workpaper before applying any rate or deduction assumption.

The change also does not authorize using the domestic treatment for an entire distributed engineering team without examining its work locations. Preserve the facts needed for that analysis: the relevant legal entities, people, service periods, contracts and locations. A vendor's billing address alone is an incomplete description of who performed the work.

Separate current spending from the old balance

The transition rules allow recovery of remaining domestic amounts capitalized for tax years beginning after 2021 and before 2025, in the first tax year beginning after 2024 or ratably over that year and the next. The separate small-business retroactive election had a July 6, 2026 deadline under Revenue Procedure 2025-28; refund limitation periods could expire earlier. The eligible-small-business test includes Section 448(c) and a tax-shelter exclusion. Revenue Procedure 2025-28, Sections 2–3 and 7.

That July deadline has passed as of this article's research date. An article offering a generic opportunity to “amend now” would omit a crucial fact. The useful next step in October is to establish what was elected, when it was filed, what balances remain and which procedures apply to the company's present position. Do not assume a missed election remains available.

Build a separate schedule for each spending year. Start with the amount originally capitalized, subtract the deductions already taken, identify adjustments, and link the closing balance to the filed return. Then add a record of any transition election and its supporting filing. Keep the original schedule even when a new treatment changes the remaining recovery pattern.

This makes a concrete difference when an acquisition, adviser change or software migration has split the records across several systems. A number labeled “remaining R&D” is much easier to challenge or correct when the calculation and source return are attached.

A deduction, a credit and engineering ROI answer different questions

A deduction changes taxable income. A research credit is a separate calculation with its own requirements. Section 70302 also changes coordination under Section 280C; stacking an unreduced credit on top of an unadjusted deduction can misstate the benefit. Public Law 119-21, Section 70302(b).

The IRS describes Form 6765 as the form used to calculate the research credit and make relevant elections. Treat that work as a separate review from the deduction schedule. IRS: About Form 6765.

Here is a deliberately simplified cash-flow illustration. Assume a company has $600,000 of spending already determined to receive an immediate deduction, enough taxable income to use it, and an assumed marginal rate of 21%. Ignoring every other interaction, the deduction's tax effect would be $126,000. It would not be a $600,000 payment from the government. If the deduction cannot reduce cash taxes in the modeled period, that cash benefit should not appear in that period's runway forecast.

Now consider the business decision behind the spending. Perhaps a new search system improved completed transactions. Its operating return would depend on attributable incremental margin, implementation costs, ongoing inference costs, human review and maintenance. The tax effect can be a separate line in the investment model. It cannot establish whether the search system worked.

Keep three outputs visible: the technical result, the pretax commercial result, and the separately reviewed tax effect. That makes a project intelligible to engineering, finance and the tax preparer without forcing them to use one misleading headline number.

Bring AI spending into the same cost story

An AI invoice is often shared by experiments, customer-facing production, internal assistants and abandoned prototypes. For management analysis, retain the invoice total and its credits, then record which usage exports or project references support an allocation. An unexplained residual should remain visible.

For example, a fictional $12,000 monthly bill might have $5,500 of usage linked to a retrieval experiment, $4,000 to production traffic and $2,500 without usable project references. That is a coverage description, not a conclusion that $5,500 qualifies under any tax provision. A reviewer still needs the activity, contract and cost analysis. Record both the proposed allocation and who accepted or changed it.

AI can help draft a list of missing project references or summarize supplied experiment notes. A good instruction is: “List each proposed connection, cite the source record, and say when the connection is uncertain.” A poor instruction asks the model to maximize eligible spending. Preserve generated suggestions separately from accepted facts so a fluent paragraph cannot silently become evidence.

A practical close package

For the next finance close, assemble a small, reviewable package:

• A register of development projects, owners, relevant entities and reporting dates.
• Payroll and contractor records linked to activities and work locations.
• Provider invoices, credits and available usage exports, with unresolved allocations retained.
• Prior-year capitalization schedules, filed returns and election records.
• A reconciliation showing how source costs, proposed treatment and return amounts connect.

The IRS's research-credit recordkeeping guidance emphasizes usable substantiation; its older audit guide is examination guidance, not independent legal authority. The practical lesson is to retain the evidence behind the calculation, rather than only its final total. IRS: Substantiation and recordkeeping.

Proforma's starting point is an initial evidence review: collect available records, describe coverage, and expose questions before a specialist finalizes tax treatment. That can begin with uploads and manual preparation. It gives the next discussion a defined set of records and decisions, instead of an unsupported savings estimate.

Sources and review scope

• Public Law 119-21, Section 70302: enacted domestic expensing and transition provisions.
• Revenue Procedure 2025-28: elections, method changes and deadlines.
• IRS Form 6765 overview: the separate credit calculation and elections.
• IRS recordkeeping audit guidance: evidence context, read with current law.

Research checked October 7, 2026. State conformity, financial-reporting treatment and company-specific filing advice are outside this article's scope.