The activity must meet the IRS four-part test:

1. Permitted purpose — developing or improving a product, process, software, technique, or formula.
2. Technological in nature — grounded in a hard science such as engineering, computer science, biology, or chemistry.
3. Elimination of uncertainty — resolving uncertainty about capability, method, or design.
4. Process of experimentation — evaluating alternatives through testing, modeling, simulation, or systematic trial and error.

Routine work, market research, and most post-production activities generally don’t qualify.

File IRS Form 6765 (Credit for Increasing Research Activities) with your timely filed federal income tax return, including extensions. The form reports the qualified research expenses (QREs) incurred during the tax year. Qualified small businesses can also elect to apply up to $500,000 of the credit against payroll taxes using Form 8974. Note: starting with 2026 tax years, most filers must also complete Form 6765’s new Section G with detailed project-level information.

For the current year, you claim the credit on your timely filed return. For years you missed, you can generally amend open tax years — typically the past three years, since the IRS statute of limitations is usually three years from the date the return was filed. Amended R&D claims require more detailed documentation and draw closer IRS scrutiny, so strong substantiation is essential.

Yes. MainStreet works alongside your existing CPA or tax preparer, not in place of them. We run the specialized R&D study, build the documentation, and prepare Form 6765, then coordinate with your CPA so the credit is filed cleanly with your return. Your accountant keeps the relationship; we bring the R&D expertise.