Schedule 3, line 6a.

1. A sole proprietor attaches Form 6765 completed through line 30. A sole proprietorship is an eligible small business when average annual gross receipts for the three prior years are $50 million or less, so line 30 goes to Form 3800, Part III, line 4i. The Form 6765 guide covers each section.
2. An owner of a partnership or S corporation takes the amount from Schedule K-1 (Form 1065), box 15, code M, or Schedule K-1 (Form 1120-S), box 13, code M, and enters it on Form 3800, Part III, line 1c (line 4i when both the entity and the owner are eligible small businesses), with the entity EIN in column (c). No Form 6765 is needed unless the individual also has research of their own.
3. Passive or not. A credit from an activity the taxpayer does not materially participate in goes in column (d) before the passive limit. Form 8582-CR figures the allowed amount, which goes on Form 3800, Part I, line 3. Otherwise use column (e). The Form 3800 guide covers the rest of the limitation.
4. Enter Form 3800, line 38 on Schedule 3, line 6a. Line 8 of Schedule 3 carries to Form 1040, line 20.
5. Report the expense. For tax years beginning after December 31, 2024, domestic research or experimental expenditures are deducted in the year paid or incurred under Section 174A, or capitalized and amortized over not less than 60 months by election. Foreign research stays under Section 174 and is amortized over 15 years. Amortized amounts are reported on Form 4562, Part VI, with 174A in column (d). Revenue Procedure 2025-28 sets out the transition choices for costs capitalized in 2022 through 2024. For a Schedule C business the current deduction is an other expense in Part V, which totals on line 48 and carries to line 27b.

A prior-year claim is filed on Form 1040-X with the completed Form 6765 (if any), Form 3800, and Schedule 3 for that year attached. A claim on an amended return must identify each business component, the research activities performed on it, and the total qualified wages, supplies, and contract research. The IRS also asks who did the work and what they set out to learn, and treats those two items as optional for now. A completed Form 6765 supplies the totals. Through January 10, 2027 the IRS allows 45 days to perfect a deficient claim before ruling on it. A year generally stays open for a refund claim until three years after its return was filed, or two years after the tax was paid if that is later.

• Schedule 3 (Form 1040) 2025
• Form 3800 (2025)
• Instructions for Form 3800 (2025)
• Form 6765 (Rev. December 2024)
• Instructions for Form 6765 (Rev. December 2025)
• Instructions for Form 4562 (2025), Part VI
• IRS: Research credit claims (Section 41) on amended returns, frequently asked questions

• Form 6765Completing Form 6765, the credit form itself.
• Form 3800Where the research credit goes on Form 3800 and how it reaches the return.
• Form 1120C corporations: Schedule J, Section 174A, and Form 1120-X.
• Form 1120-SS corporations: Schedule K line 13g, K-1 box 13 code M, and the shareholder.
• Form 1065Partnerships: Schedule K line 15f, K-1 box 15 code M, and the partner.
• Form 1041Estates and trusts: Schedule G line 2b and K-1 box 13 code I.