Updated October 18, 2026. Quick answer: Line 8 is the AMT foreign tax credit, which you only fill in when line 10 is smaller than line 7. Line 9 subtracts it from line 7. Line 10 is your regular tax after certain credits, and line 11 subtracts line 10 from line 9 and carries the AMT to Schedule 2.
More IRS forms and schedules, read line by line: Form 8801 instructions.
Line 8: the AMT foreign tax credit
The caption is “Alternative minimum tax foreign tax credit (see instructions)”. “The AMTFTC is a credit that you can claim against the AMT.” “You will figure the AMTFTC using the same limitation rules that apply to the foreign tax credit for regular tax purposes, but with AMT amounts.” The regular foreign tax credit form is introduced on the Form 1116 page.
Do you need to fill it in? “Before figuring your AMTFTC, figure your foreign tax credit for the regular tax and complete Schedule 3 (Form 1040), line 1.” “Next, fill in Form 6251, line 10, as instructed.” Then compare the two lines. “If the amount on line 10 is greater than or equal to the amount on line 7, do the following.” “Leave line 8 blank and enter-0-on line 11.” “If the amount on line 10 is less than the amount on line 7, figure your AMTFTC and enter it on line 8.” Schedule 3 line 1 is on the Schedule 3 line 1 page.
How to figure line 8
If you claimed the regular credit without Form 1116: “If you made an election to claim the foreign tax credit on your 2025 tax return without filing Form 1116, your AMTFTC is the same as the foreign tax credit on Schedule 3 (Form 1040), line 1.” “Enter that amount on Form 6251, line 8.”
Otherwise the instructions give steps. Step 1: “Separate your foreign source income into categories.” “Complete a separate AMT Form 1116 for each separate category of income.” Step 6 ends the process: “Enter on Form 6251, line 8, the amount from line 35 of the first AMT Form 1116.” The steps in between are in the instructions and this page does not copy them.
“Attach to your tax return, after Form 6251, all AMT Forms 1116 (and, if applicable, Schedule B (Form 1116)) you used to figure your AMTFTC.” “But don’t attach AMT Forms 1116 if your AMTFTC is the same as your regular tax foreign tax credit.”
An unused credit may carry over: “If your AMTFTC is limited, the unused amount may generally be carried back or forward according to section 904(c).” “any unused AMTFTC for 2025 can’t be carried back or forward.” That last sentence applies if you made the election to claim the credit without Form 1116. A simplified option also exists: “You may elect to use a simplified section 904 limitation to figure your AMTFTC.”
Lines 9 and 10
Line 9: “Tentative minimum tax. Subtract line 8 from line 7.”
Line 10 starts from the regular tax. The form says “Add Form 1040 or 1040-SR, line 16 (minus any tax from Form 4972), and Schedule 2 (Form 1040), line 1z.” “Subtract from the result Schedule 3 (Form 1040), line 1 and any negative amount reported on Form 8978, line 14 (treated as a positive number). If zero or less, enter -0-.” If you used income averaging: “If you used Schedule J to figure your tax on Form 1040 or 1040-SR, line 16, refigure that tax without using Schedule J before completing this line.” “This is only for Form 6251; don’t change the amount on Form 1040, 1040-SR, or 1040-NR, line 16.”
The related Form 1040 lines are explained at Form 1040 lines 17 and 18.
Line 11: the AMT
The caption reads “AMT. Subtract line 10 from line 9. If zero or less, enter -0-. Enter here and on Schedule 2 (Form 1040), line 2”. For Form 1040-NR filers the instructions say “enter the amount from line 11 on Schedule 2 (Form 1040), line 2.” Schedule 2 is covered on the Schedule 2 lines 2 and 3 page.
A computed illustration, not an IRS example, with round numbers chosen only to show the subtraction: if line 7 were $50,000 and line 8 were $12,000, computed line 9 would be $38,000. If line 10 were $30,000, computed line 11 would be $8,000.
Where the number comes from
Line 7 is on the lines 5 to 7 page. Line 8 comes from the AMTFTC steps above, line 10 comes from your regular tax, and lines 9 and 11 are subtractions.
Where it goes next
Line 11 goes to Schedule 2. Part III, if you complete it, supplies line 7. It is on the Part III page.
Edition and line numbers
This page reads the 2025 Form 6251 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
- Filling in line 8 when line 10 is at least as big as line 7. The instructions say “If the amount on line 10 is greater than or equal to the amount on line 7, do the following.” The first step is to leave line 8 blank.
- Changing Form 1040 when refiguring line 10. The instructions say “This is only for Form 6251; don’t change the amount on Form 1040, 1040-SR, or 1040-NR, line 16.”
- Attaching AMT Forms 1116 when they are not needed. The instructions say “But don’t attach AMT Forms 1116 if your AMTFTC is the same as your regular tax foreign tax credit.”
Related: Form 1116, Schedule 3 line 1, Schedule 2 lines 2 and 3, Form 1040 lines 17 and 18, and Form 6251.
Sources
- Instructions for Form 6251, Alternative Minimum Tax, Individuals (2025): https://www.irs.gov/pub/irs-pdf/i6251.pdf
- Form 6251, Alternative Minimum Tax, Individuals (2025): https://www.irs.gov/pub/irs-pdf/f6251.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.