U.S. · Tax forms
Schedule 2 line 21, total other taxes.
The lines it adds, the ones it leaves out, and where the total goes.
Line 21 (“Add lines 4, 7 through 16, 18, and 19. These are your total other taxes.”) totals Part II of Schedule 2. Enter it on Form 1040 or 1040-SR, line 23, or on Form 1040-NR, line 23b. Line 3 (Part I) is not included here; it goes to line 17.
Look up a line item
Result
Lines that feed line 21 (2025 Schedule 2, Part II)
| Line | Label on the 2025 form | Form instruction |
|---|---|---|
| Line 4 | Self-employment tax | Attach Schedule SE; boxes for exemptions (Forms 4361, 4029 and others, see instructions) |
| Line 7 | Total additional social security and Medicare tax. Add lines 5 and 6 | Line 5 (Form 4137) plus line 6 (Form 8919); lines 5 and 6 are not added separately |
| Line 8 | Additional tax on IRAs or other tax-favored accounts | Attach Form 5329 if required; if not required, check the box |
| Line 9 | Household employment taxes | Attach Schedule H |
| Line 10 | Reserved for future use | Nothing to enter |
| Line 11 | Additional Medicare Tax | Attach Form 8959 |
| Line 12 | Net investment income tax | Attach Form 8960 |
| Line 13 | Uncollected social security and Medicare or RRTA tax on tips or group-term life insurance from Form W-2, box 12 | Amount from W-2 box 12 |
| Line 14 | Interest on tax due on installment income from the sale of certain residential lots and timeshares | See instructions |
| Line 15 | Interest on the deferred tax on gain from certain installment sales with a sales price over $150,000 | Interest under section 453A(c) |
| Line 16 | Recapture of low-income housing credit | Attach Form 8611; amount from Form 8611, line 14 |
| Line 18 | Total additional taxes. Add lines 17a through 17z | Subtotal of the other additional taxes list on line 17 |
| Line 19 | Recapture of net EPE from Form 4255, line 1d, column (l) | Amount from Form 4255 |
Lines that are in the sum, and lines that are not
The printed instruction says to add line 4, lines 7 through 16, line 18 and line 19. Line 17 is a list (17a through 17z), so its subtotal on line 18 is used instead of the individual entries. Lines 5 and 6 flow through line 7, so they are not added a second time. The 2025 form also shows line 20 (Section 965 net tax liability installment from Form 965-A) after line 19; it is not in the instruction to add.
Where it goes
The Schedule 2 instructions: “Enter the amount on Schedule 2, line 21, on Form 1040 or 1040-SR, line 23; or 1040-NR, line 23b.” That is the other-taxes line of the return, separate from line 17, which receives Part I.
Self-employment tax is usually the biggest piece
For many filers, line 4 is most of line 21. It comes from Schedule SE, and the deductible part of it (Schedule SE line 13) is reported on Schedule 1 line 15, so the same Schedule SE work feeds two different forms.
Worked example
Luis has self-employment tax of $6,000 (line 4), an additional tax of $800 on an early IRA distribution (line 8), household employment taxes of $1,500 for a nanny (line 9) and additional Medicare Tax of $450 (line 11). Line 21 = 6,000 + 800 + 1,500 + 450 = $8,750, entered on Form 1040 line 23. Names and figures are made up.
More line pages in this set
Related lines: Schedule 2 line 3, Schedule 2 line 8.
Sources
- Instructions for Form 1040 and 1040-SR (2025): the Schedule 2 line instructions on this page. Schedule 2 instructions: “Enter the amount on Schedule 2, line 21, on Form 1040 or 1040-SR, line 23; or 1040-NR, line 23b.” Page last reviewed or updated May 7, 2026. Read November 2, 2026.
- Schedule 2 (Form 1040) 2025: the printed line labels and arithmetic. Read November 2, 2026.
Tax year 2025 form and instructions. Line numbers and labels can shift between years, so check them against the form for your tax year. Names in worked examples are made up.
Frequently asked questions
What is Schedule 2 line 21?
Your total other taxes: add lines 4, 7 through 16, 18 and 19 of Schedule 2.
Where does line 21 go?
On Form 1040 or 1040-SR, line 23, or on Form 1040-NR, line 23b.
Why is line 17 not in the sum?
Line 17 is a list of other additional taxes (17a through 17z). Line 18 totals them, and line 18 is what line 21 adds.
Is line 3 part of line 21?
No. Line 3 is the Part I total (additions to tax and AMT) and is included in Form 1040 line 17.
Are lines 5 and 6 added separately?
No. Line 7 adds lines 5 and 6, and line 21 includes line 7.
Not tax advice
This page summarizes IRS instructions, mostly written for the people who prepare the form, and is not tax, legal or financial advice. A CPA or an enrolled agent can confirm what a line means for your return. Everything runs in your browser; nothing you enter is sent anywhere.