Updated October 17, 2026. Quick answer: Line 12 of Form 1040 is where you take either the standard deduction or your itemized deductions. Lines 12a to 12d are check boxes that tell you which standard deduction applies, and line 12e holds the amount you use. The standard deduction comes from the amounts printed on the form or from a chart or worksheet in the instructions, and itemized deductions come from Schedule A.
IRS worksheets read line by line: W-4 Deductions Worksheet.
More IRS forms and schedules for individual filers, read line by line: who can still use Form 2106.
Related reading on this site: IRS Publication 501.
Read box by box from the IRS form text: Form W-2G box 1 and Form W-2G slot machine winnings.
Form lines read one part at a time: Form 4684 Section A.
IRS worksheets read line by line: Worksheet 2, Recoveries of Itemized Deductions.
Business use of your home (Form 8829), the saver’s credit (Form 8880), clean vehicle credits (Form 8936) and amended returns (Form 1040-X), read line by line: Form 8829 lines 16 to 27, Form 1040-X lines 1 to 3 and Form 1040-X lines 4a to 5.
IRS worksheets from the 2025 Form 1040 instructions, read line by line: Standard Deduction Worksheet for Dependents and State and Local Income Tax Refund Worksheet.
Foreign tax credit (Form 1116) and alternative minimum tax (Form 6251) for 2025, read line by line: Form 1116 lines 2 to 5, Form 6251 line 1 and Form 6251 line 2a.
Schedule A and Schedule B (Form 1040) for 2025, read line by line: Schedule A lines 1 to 4, Schedule A lines 5d and 5e and Schedule A line 17.
What line 12 asks for
Line 12 has five parts. The form’s caption for the amount line reads “Standard deduction or itemized deductions (from Schedule A)”. Above it, boxes 12a to 12d ask a few yes or no questions about you and your spouse. The instructions open the topic with a plain comparison: “In most cases, your federal income tax will be less if you take the larger of your standard deduction or itemized deductions.” The rest of the return is mapped in Form 1040 line by line.
The check boxes on lines 12a to 12d
Line 12a is about being claimed by someone else. The instructions say “If you or your spouse (if you are married and filing a joint return) can be claimed as a dependent on someone else’s return, check the appropriate box(es) on line 12a.”
Line 12b is about a spouse who itemizes: “If your filing status is married filing separately and your spouse itemizes deductions on their return, check the box on line 12b.”
Line 12c is about dual-status aliens: “If you were a dual-status alien, check the box on line 12c.” The instructions give a carve-out: if you were a dual-status alien and file a joint return with a spouse who was a U.S. citizen or resident alien at the end of 2025, and you both agree to be taxed on your combined worldwide income, you don’t check the box. They send you to the earlier section on nonresident aliens and dual-status aliens for the details.
Line 12d is about age and blindness. The instructions say “If you or your spouse (if you are married and filing a joint return) were born before January 2, 1961, or were blind at the end of 2025, check the appropriate box(es) on line 12d.”
Blindness and a spouse who died in 2025
For the blindness box the instructions require proof: “If you weren’t totally blind as of December 31, 2025, you must get a statement certified by your eye doctor (ophthalmologist or optometrist)”. They also say “You must keep the statement for your records.”
If your spouse died in 2025 the age box has its own rule: “If your spouse was born before January 2, 1961, but died in 2025 before reaching age 65, don’t check the box that says” that the spouse was born before January 2, 1961. For a return prepared for someone who died in 2025 the instructions point elsewhere: “see Pub. 501 before completing the standard deduction information.”
Where the standard deduction comes from
The instructions explain where to look: “Most Form 1040 filers can find their standard deduction by looking at the amounts listed to the left of line 12e.” Those amounts are printed in the margin of the form and are not repeated on this page; read them from the form for your filing status. The same sentence for the other form reads “Most Form 1040-SR filers can find their standard deduction by using the chart on the last page of Form 1040-SR.” The 2025 standard deduction is also covered on the standard deduction 2025 page.
Some filers do not use the margin amounts. The instructions list the exceptions. For a dependent: “If you checked a box on line 12a, use the Standard Deduction Worksheet for Dependents to figure your standard deduction.”
For a spouse who itemizes on a separate return: “If you checked the box on line 12b, your standard deduction is zero, even if you were born before January 2, 1961, or were blind.” For a dual-status alien the instructions say the same thing about line 12c: “If you checked the box on line 12c, your standard deduction is zero, even if you were born before January 2, 1961, or were blind.”
For age or blindness: “If you checked any box on line 12d, figure your standard deduction by using the Standard Deduction Chart for People Who Were Born Before January 2, 1961, or Were Blind if you are filing Form 1040 or by using the chart on the last page of Form 1040-SR.” The chart’s amounts are in the instructions and are not copied here.
A last exception concerns disaster losses: “If you had a net qualified disaster loss and you elect to increase your standard deduction by the amount of your net qualified disaster loss, use Schedule A to figure your standard deduction.”
Where itemized deductions come from
If you itemize, the instructions say “To figure your itemized deductions, fill in Schedule A.” The form’s own caption on line 12e points the same way, to Schedule A. Schedule A is explained on the Schedule A page. The amount from Schedule A goes on line 12e.
The instructions add a note about one kind of deduction that does not belong on this line: “don’t report the deduction on line 12e.” That sentence concerns a deduction under section 250 tied to a section 962 election, and the instructions say the related tax is reported on line 16 instead. See line 16.
Where it goes next
Line 12e feeds the deductions total. The form’s caption for line 14 reads “Add lines 12e, 13a, and 13b”. So the amount on line 12e is added to the qualified business income deduction on line 13 and to the additional deductions from Schedule 1-A. The sum and the taxable income that follows are explained on lines 14 and 15.
Edition and line numbers
This page reads the 2025 Form 1040 and its 2025 instructions, the current files irs.gov served on 2026-10-17. They are the forms for the tax year 2025 return, filed in 2026. The instructions say “The lines on Forms 1040 and 1040-SR are the same.” so everything here applies to Form 1040 and to Form 1040-SR alike. The check boxes and the line 12e wording are as quoted above. 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
- Ignoring a line 12a to 12d box. The instructions say “If you checked any box on line 12d, figure your standard deduction by using the Standard Deduction Chart”, so a checked box changes where the amount comes from.
- Taking a standard deduction when line 12b applies. The instructions say “your standard deduction is zero, even if you were born before January 2, 1961, or were blind.”
- Entering the dependent amount from the margin of the form. The instructions say “use the Standard Deduction Worksheet for Dependents to figure your standard deduction.” That applies when you checked a box on line 12a.
Related: Standard deduction 2025, Schedule A (Form 1040), Form 1040, and Form 1040-SR.
Sources
- Instructions for Form 1040 and Form 1040-SR (2025): https://www.irs.gov/pub/irs-pdf/i1040gi.pdf
- Form 1040, U.S. Individual Income Tax Return (2025): https://www.irs.gov/pub/irs-pdf/f1040.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.