Updated October 18, 2026. Quick answer: Line 1 is your adjusted gross income copied from Form 1040. Lines 2a to 2d add back certain excluded income, such as income from Puerto Rico. Line 3 adds lines 1 and 2d, and that total is the modified AGI the credit uses.
What lines 1 to 3 ask for
The form’s captions read “Enter the amount from line 11a of your Form 1040, 1040-SR, or 1040-NR” for line 1, “Enter income from Puerto Rico that you excluded” for line 2a, and “Add lines 1 and 2d” for line 3. The instructions have no separate paragraph for these three lines, so the form’s own captions are the guide. This page is part of the Schedule 8812 walk-through.
Line 1: AGI from Form 1040
Line 1 is a copy. The adjusted gross income on your return is explained on the Form 1040 AGI page. Enter the amount from the line the caption names, on the form for your return.
Line 2: income you excluded
Line 2 has three entry lines. The captions are “Enter income from Puerto Rico that you excluded”, “Enter the amounts from lines 45 and 50 of your Form 2555”, and “Enter the amount from line 15 of your Form 4563”. Line 2d then says “Add lines 2a through 2c”.
The instructions describe Puerto Rico residency this way: “Generally, you were a bona fide resident of Puerto Rico if, during 2025, you:” They then list three conditions, which include having met the presence test. For more, they say “For more information on bona fide resident status, see Pub. 570.”
Line 3: modified AGI
The instructions say “For purposes of the CTC and ODC, your modified AGI is the amount on line 3 of Schedule 8812.” So line 3 is the income figure the later lines test against the filing-status amount. That step is on the lines 9 to 14 page.
Where the number comes from
Line 1 comes from your Form 1040. Lines 2a to 2c come from income you excluded and from the forms named in the captions, and line 2d totals them. If you excluded nothing, those lines have nothing to add. The wages and other earned income that feed your return are explained at Form 1040 line 1a.
Where it goes next
Line 3 is used on line 10, where the form says “Subtract line 9 from line 3.” The lines for counting children and other dependents are on the lines 4 to 8 page.
Edition and line numbers
This page reads the 2025 Schedule 8812 (Form 1040), Credits for Qualifying Children and Other Dependents and its 2025 instructions, the current files irs.gov served on 2026-10-18. They are the files for the tax year 2025 return, filed in 2026. The form’s own header says “Attach to Form 1040, 1040-SR, or 1040-NR.” Check the tax year printed on the form you are filling in and use the line numbers on that year’s form, because a different year’s form can number or word its lines differently.
Common mistakes
- Skipping line 2 because the amounts seem not to apply. Line 2a is described as “Enter income from Puerto Rico that you excluded”.
- Treating line 3 as plain AGI. The form says “Add lines 1 and 2d”.
- Using a different number for modified AGI elsewhere. The instructions say “your modified AGI is the amount on line 3 of Schedule 8812.”
Related: Form 1040 AGI, Form 1040 line 1a, child tax credit, and Form 1040.
Sources
- Instructions for Schedule 8812 (Form 1040), Credits for Qualifying Children and Other Dependents (2025): https://www.irs.gov/pub/irs-pdf/i1040s8.pdf
- Schedule 8812 (Form 1040), Credits for Qualifying Children and Other Dependents (2025): https://www.irs.gov/pub/irs-pdf/f1040s8.pdf
Read from the IRS documents linked above on October 18, 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.