Updated October 17, 2026. Quick answer: Lines 13a to 13d are four separate entries under the heading for other payments or refundable credits: Form 2439 on 13a, the section 1341 credit on 13b, a net elective payment election amount from Form 3800 on 13c, and a deferred section 965 amount on 13d. Each takes its figure from the form or record the instructions name.
Read box by box from the IRS form text: Form 2439 box 2.
Line 13a: Form 2439
The schedule’s caption for line 13a is only “Form 2439”, under the heading “Other payments or refundable credits:”. The Form 1040 instructions have no separate paragraph for 13a, so the schedule’s caption is the only description of the line.
Line 13b: section 1341 credit
The schedule describes line 13b as “Section 1341 credit for repayment of amounts included in income from earlier” years. The instructions say: “If you are claiming a credit for repayment of amounts you included in your income in an earlier year because it appeared you had a right to the income, enter the amount on line 13b.” For the details the instructions point elsewhere: “See Pub. 525 for details about this credit.”
Line 13c: net elective payment election amount
The caption reads “Net elective payment election amount from Form 3800, Part III, line 6, column (j)”. The instruction is “Enter any net elective payment election amount from Form 3800, Part III, line 6, column (j).”
Line 13d: deferred section 965 amount
The caption reads “Deferred amount of net 965 tax liability (see instructions)”. If you elected to pay your net 965 tax liability in installments, the instruction is to “report the deferred amount on line 13d.” It then says what to enter: “Enter the amount of net 965 tax liability remaining to be paid in future years.”
Where it goes next
Lines 13a to 13d, with 13z, are added on line 14, which the schedule describes as “Total other payments or refundable credits. Add lines 13a through 13z”. Line 14 then feeds line 15. See Schedule 3 lines 13z, 14 and 15 for those steps, Schedule 3 line 12 for the line before, and the Form 1040 lines 29, 30 and 31 page for the Form 1040 side.
Edition and line numbers
This page reads the 2025 Schedule 3 (Form 1040) and the 2025 Form 1040 instructions, the current files irs.gov served on 2026-10-17. They are the files for the tax year 2025 return, filed in 2026. The schedule says “Attach to Form 1040, 1040-SR, or 1040-NR.” Its line instructions are part of the Form 1040 instructions, under the heading “Instructions for Schedule 3”. Check the tax year printed on the schedule you are filling in and use the line numbers on that year’s schedule, because a different year’s schedule can number or word its lines differently.
Common mistakes
- Looking for a line 13a rule that is not there. The only caption is “Form 2439”, with no further instruction paragraph.
- Putting the section 1341 repayment on the wrong line. The instructions say “enter the amount on line 13b.”
- Entering the original section 965 amount on 13d. The instructions say “Enter the amount of net 965 tax liability remaining to be paid in future years.”
Related: Form 1040 lines 29, 30 and 31, Form 1040 line by line, and Form 1040.
Sources
- Instructions for Form 1040 and Form 1040-SR (2025): https://www.irs.gov/pub/irs-pdf/i1040gi.pdf
- Schedule 3 (Form 1040), Additional Credits and Payments (2025): https://www.irs.gov/pub/irs-pdf/f1040s3.pdf
Read from the IRS documents linked above on October 17, 2026. General information, not tax advice. Your own facts decide the outcome, and a preparer, the account provider or the IRS is the right place to confirm anything consequential.