Key IRS R&D Credit Dates Every 2026 Filer Needs to Know

The R&D credit compliance landscape has changed substantially over the past two years and the changes are not finished. New form requirements, amended return documentation rules, and mandatory project-level disclosure have created a set of deadlines that matter regardless of company size or industry. For companies currently finishing 2025 returns, planning ahead for the 2026 tax year, or working through amended return claims from prior years, the following dates determine what is required and when.

What Is Already in Effect

June 18, 2024. This is the date after which any amended return claiming an R&D credit refund must include specific documentation at the time of filing: business component identification, individual activity descriptions, and QRE breakdowns. The Chief Counsel memo standard that has been in place since 2021 is now a hard requirement for amended return filers. You cannot file a bare-bones claim and supplement it later. The documentation needs to accompany the return.

This has caught companies off guard, particularly those filing amended returns for prior tax years to capture credits they originally missed. If you are in the middle of an amended return project or planning one, make sure your documentation is at the required level before the return goes out.

The 2025 Tax Year (Currently Filing)

February 5, 2026. The IRS released finalized Form 6765 instructions for tax year 2025. Two changes apply to returns being filed right now.

Section E is required for all filers. It asks for the total number of business components generating QREs, total officer wages included in QREs, whether you used the ASC 730 Directive, whether any QREs relate to an acquisition or disposition during the year, and whether any new expense categories were added this year that were not in prior base years. These are new disclosure items with no prior equivalent on the form. Every company claiming the R&D credit for 2025 needs to complete them.

Section G remains optional for 2025. The IRS extended the stakeholder comment period on draft instructions through March 31, 2026, and finalized the instructions in February. Section G is not required for this filing cycle, but completing it voluntarily is worth serious consideration.

The case for completing it: voluntary completion this year functions as a test. You will learn whether your documentation infrastructure can produce what Section G requires: project-level component identification, wage breakdowns by activity type, expense allocations by component, and usable descriptions. If the answer is yes, you file a stronger return and you are ready for 2026. If the answer is no, you find out with time to fix it rather than discovering the gap when Section G is mandatory.

The 2026 Tax Year: Section G Becomes Mandatory

For tax year 2026, Section G becomes mandatory for most filers. This is the most significant compliance change since the R&D credit was established, because it transforms what has historically been a year-end calculation exercise into a year-round documentation process.

The exceptions are narrow: qualified small businesses under Section 41(h)(3) electing the payroll tax credit, and taxpayers with QREs of $1.5 million or less and gross receipts of $50 million or less measured at the control group level on an originally filed return. If you do not fit those criteria, Section G is required.

What Section G requires for each business component in your top 80% of QREs, up to 50 components:

• A description of the business component: what product, process, software, technique, formula, or invention was being researched.
• Wages for direct research activities, meaning the work of individuals who actually performed the research.
• Wages for supervisory activities, meaning the work of individuals who directly supervised those performing the research.
• Wages for support activities, meaning the work of individuals who directly supported the research.
• Supply expenses allocated to the component.
• Contract research expenses allocated to the component.

Companies that have project-level time tracking and expense coding will be able to produce this data. Companies that have been doing R&D credits with department-level estimates and year-end reconciliations will not, not without building new systems. The 2026 tax year begins January 1 for calendar-year filers. The window to build the necessary infrastructure is closing.

January 10, 2027: Amended Return Perfection Window Closes

The IRS established a 45-day perfection period for amended return claims that are returned as not perfected due to missing documentation. If a claim is returned, the taxpayer has 45 days to provide the missing information. That perfection accommodation was extended through January 10, 2027.

After that date, the transition period ends. Claims that are returned as not perfected after January 2027 will be subject to the standard rules without the accommodation. If you are filing amended return claims in the next several months, the January 2027 date is a hard backstop.

Planning by Filing Category

For 2025 returns being finalized now: complete Section E in full, double-check your officer wage disclosure, and seriously consider completing Section G voluntarily as a readiness assessment.

For 2026 tax year planning: get project-level time tracking in place before the calendar year closes. Build contemporaneous documentation habits now, component descriptions written during the project, technical uncertainty documented as it occurs, alternative approaches recorded when they are being evaluated. Do not wait until filing season to figure out whether your records support Section G.

For amended return filers: documentation needs to be complete at filing, not assembled in response to a perfection request. Use the remaining transition window to get prior-year claims in order.

One additional note on timing that is worth building into any planning: LB&I staffing reductions have created examination and appeals backlogs. Cases are taking longer to assign and longer to resolve. If your company is currently in an examination or anticipates opening one, extend your timeline assumptions accordingly.

Want to talk through where your company stands on any of this? Reach out. We would love to help you think it through.

Jason Massie, CPA, Esq.

As the Founder and President of MASSIE R&D Tax Credits, Jason is responsible for the quality, consistency, and integrity of our services. His strategic vision and leadership drive innovation within the company, encouraging collaboration and ne...