Updated October 18, 2026. Quick answer: The Student Loan Interest Deduction Worksheet figures the amount of student loan interest you can deduct on Schedule 1, line 21. It starts from the interest you paid, then reduces it if your modified income is over a threshold. Line 9 is the deduction, and it is entered on Schedule 1, line 21.
Related reading on this site: IRS Publication 970.
What this worksheet is for
“Use the worksheet in these instructions to figure your student loan interest deduction.” The instructions open the line with a list of conditions: “You can take this deduction only if all of the following apply.” The first two are “You paid interest in 2025 on a qualified student loan” and “Your filing status is any status except married filing separately.”
Some filers use a different publication: “Use Pub. 970 instead of the worksheet in these instructions to figure your student loan interest deduction if you file Form 2555 or 4563”, “or you exclude income from sources within Puerto Rico.” The line itself is explained on Schedule 1 lines 21 to 23, and the other worksheets in this series are on the Form 1040 worksheets page.
The worksheet line by line
The two filing status amounts on line 5 are printed on the worksheet and are not repeated here.
| Line | What the worksheet says |
|---|---|
| Before you begin | “Be sure you have read the Exception in the instructions for this line to see if you can use this worksheet” |
| 1 | “Enter the total interest you paid in 2025 on qualified student loans” and the line says not to “enter more than $2,500” |
| 2 | “Enter the amount from Form 1040 or 1040-SR, line 9” |
| 3 | “Enter the total of the amounts from Schedule 1, lines 11 through 20, and 23 and 25” |
| 4 | “Subtract line 3 from line 2” |
| 5 | “Enter the amount shown below for your filing status.” Two amounts are printed under the line, one for single, head of household or qualifying surviving spouse and one for married filing jointly; read yours on the worksheet. |
| 6 | “Is the amount on line 4 more than the amount on line 5?” If No, “Skip lines 6 and 7” and “go to line 9”. If Yes, “Subtract line 5 from line 4” |
| 7 | “Divide line 6 by $15,000 ($30,000 if married filing jointly).” “Enter the result as a decimal (rounded to at least three places).” “If the result is 1.000 or more, enter 1.000” |
| 8 | “Multiply line 1 by line 7” |
| 9 | “Student loan interest deduction. Subtract line 8 from line 1.” “Enter the result here and on Schedule 1, line 21.” |
A worked example
This example is an illustration, not an IRS example. Every figure is invented except the line 5 amount, which for a single filer is the $85,000 the worksheet prints. It assumes a single filer, so the divisor is the $15,000 printed first on line 7.
| Line | Input or step (illustration, not an IRS example) | Amount |
|---|---|---|
| Line 1 | Interest paid on qualified student loans | $1,800 |
| Line 2 | Form 1040, line 9 | $89,000 |
| Line 3 | Schedule 1 amounts on line 3 | $1,000 |
| Line 4 | Line 2 minus line 3 | $88,000 (computed) |
| Line 5 | Single filer: the amount printed for single, head of household or qualifying surviving spouse | $85,000 |
| Line 6 | Line 4 minus line 5 | $3,000 (computed) |
| Line 7 | Line 6 divided by 15,000 (the single filer divisor printed on line 7) | 0.200 |
| Line 8 | Line 1 times line 7 | $360 (computed) |
| Line 9 | Line 1 minus line 8 | $1,440 (computed) |
Because line 4 is more than line 5, the worksheet reduces the interest by line 8, and the deduction on line 9 is smaller than the interest paid.
Where the number comes from
Line 1 is your interest. A lender’s statement is the usual source, and the box is described on the Form 1098-E box 1 and box 2 page. The instructions define the loan: “A qualified student loan is any loan you took out to pay the qualified higher education expenses for any of the following individuals who were eligible students.”
Line 2 comes from Form 1040, line 9, and line 3 from Schedule 1. Together with line 4 they give the modified figure the instructions refer to: “Use lines 2 through 4 of the worksheet in these instructions to figure your modified AGI.” Line 9 and line 10 of Form 1040 are explained on lines 9, 10 and 11.
Where it goes next
Line 9 says “Enter the result here and on Schedule 1, line 21.” The line also says: “Don’t include this amount in figuring any other deduction on your return”, so the same interest is not counted again elsewhere. The amount continues from Schedule 1 to Form 1040.
Edition and line numbers
This page reads the 2025 Instructions for Form 1040 and 1040-SR, the current file irs.gov served on 2026-10-18, byte-identical to the archived copy; the worksheet is for the tax year 2025 return, filed in 2026. Check the tax year printed on the worksheet in your own instructions and use that year’s line numbers, because a different year’s worksheet can number or word its lines differently.
Common mistakes
- Entering all the interest paid regardless of the cap. Line 1 says not to “enter more than $2,500”
- Using this worksheet when Form 2555 is filed. The instructions say “Use Pub. 970 instead of the worksheet in these instructions to figure your student loan interest deduction if you file Form 2555 or 4563”
- Claiming the deduction on a married filing separately return. The conditions require “Your filing status is any status except married filing separately.”
Related: Schedule 1 lines 21 to 23, Form 1098-E box 1 and box 2, lines 9, 10 and 11, and Schedule 1.
Sources
- Instructions for Form 1040 and 1040-SR (2025): https://www.irs.gov/pub/irs-pdf/i1040gi.pdf
- Form 1040 (2025): https://www.irs.gov/pub/irs-pdf/f1040.pdf
- Schedule 1 (Form 1040), Additional Income and Adjustments to Income (2025): https://www.irs.gov/pub/irs-pdf/f1040s1.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.