Part I. Credits Not Allowed Against

Line 1 Non-passive credits from Part III, line 2: Combine column (e) with non-passive amounts from column (f).

Caution: Do not take into account any amount in column (f) from passive activities. See Transfer of Eligible Credits Under Section 6418 and Transferees of Eligible Credits Under Section 6418 , later.

Line 2 Report on line 2 the total of all passive activity credit amounts included on Part III, line 2, column (d); and passive amounts included on Part III, line 2, column (f); and Part IV, line 6, column (d). See Transferee taxpayer under Transferees of Eligible Credits Under Section 6418 .

Instructions for Form 3800 (2025) 5

Line 3 Enter the applicable passive activity credit amount allowed from Form 8582-CR, Passive Activity Credit Limitations; or Form 8810, Corporate Passive Activity Loss and Credit Limitations. The passive activity credit amount allowed on Part I, line 3, only applies to the general business credits not allowed against TMT from Part I, line 2. Do not include specified credits on line 3.

If no credits are allowed, enter -0- on line 3.

Line 4 Enter the amount of non-passive carryforwards to 2025 of unused credits that are reported from line 6 of Part IV, column (f).

Check the box. For each credit entered on line 4, if the credit amount was changed or revised from the amount originally reported, check the box on this line and see the instructions for Part IV and Part VI (if applicable) for the required statement.

Adjustment for the payroll tax credit. A qualified small business that elected on Form 6765 to claim a portion of its research credit as a payroll tax credit must reduce its research credit carryforward by the amount elected as a payroll tax credit.

Line 5 Use Part I, line 5, only when you amend your 2025 return to carry back unused credits from 2026. Enter the non-passive amount that is reported from line 6 of Part IV, column (f).

Note: Individuals claiming the research credit from a sole proprietorship or pass-through entity don’t include any carryback of that credit on Part I, line 5, before figuring the limitation on Part III, line 1c. Include the carryback when figuring the research credit limitation on line 1c of Part III. Then, include the allowable carryback amount on Part I, line 5. See Required statement, later, and attach the statement to your return.