Schedule 1 Line 24z is the write-in catch-all for above-the-line adjustments to income that the tax code allows but that don’t have their own numbered line on the 2025 Schedule 1. If your adjustment already has a dedicated line (24a through 24k, or anywhere on Lines 11 through 23), it goes there instead. Most filers never touch 24z.
Check the Named Lines First
Before writing anything on 24z, confirm your item isn’t already assigned a line. Several adjustments that used to live in the “other” bucket now have their own slot, and the IRS has been narrowing 24z year by year. If you’re working from an older guide, verify against the current form.
Lines 24a through 24k on the 2025 Schedule 1 cover:
- 24a: Jury duty pay you turned over to your employer.
- 24b: Expenses from renting personal property for profit when it isn’t a full trade or business (matched to income reported on Line 8l).
- 24c: The nontaxable value of Olympic or Paralympic medals and USOC prize money, for athletes with AGI at or below $1 million ($500,000 if married filing separately).
- 24d: Reforestation amortization and expenses under IRC Section 194, for qualified timber property amortized over 84 months (up to $10,000 per year, or $5,000 for married filing separately).
- 24e: Repayment of supplemental unemployment benefits under the Trade Act of 1974.
- 24f: Contributions to Section 501(c)(18)(D) pension plans.
- 24g: Contributions by certain chaplains to Section 403(b) plans.
- 24h: Attorney fees and court costs for actions involving unlawful discrimination claims.
- 24i: Attorney fees and court costs connected to an IRS whistleblower award.
- 24j: Housing deduction from Form 2555 (foreign earned income).
- 24k: Excess deductions of Section 67(e) expenses from Schedule K-1 (Form 1041).
A few adjustments filers sometimes mistake for 24z items sit higher in Part II: reservist, performing artist, and fee-basis government official business expenses on Line 12 (reported using Form 2106); educator expenses on Line 11 (up to $300 per eligible educator); and Archer MSA contributions on Line 23 (calculated on Form 8853). None of those belong on 24z.
What Actually Goes on Line 24z
After the named lines are accounted for, Line 24z is for any remaining adjustment the tax code authorizes but the form doesn’t specifically list. These are edge cases.
One example is the exclusion for energy conservation subsidies under IRC Section 136. If a public utility gives you a subsidy to install energy-efficient equipment in your home, the subsidy is excluded from gross income. When the amount shows up on a tax information form, an offsetting 24z entry can back it out of reported income.
Other 24z candidates include deductions authorized by newer legislation that the IRS hasn’t yet assigned to a dedicated line, or adjustments arising from specific IRS guidance issued during the tax year. Because the contents of a catch-all line shift with the form and the code, don’t rely on a prior year’s placement without rechecking.
1099-K Sales of Personal Items: No Longer a 24z Item
Line 24z gained visibility during the 1099-K rollout. Payment platforms like PayPal and Venmo, along with online marketplaces, issue a 1099-K reporting gross proceeds. If you sold personal items at a loss, the form still shows the full proceeds as though they were income.
For 2022 and 2023, the IRS allowed taxpayers to report the gross amount on Line 8z and enter an offsetting negative amount on Line 24z to zero out the non-taxable portion. Starting with tax years beginning in 2024, that method is out. You now report 1099-K amounts in the entry space at the top of Schedule 1 instead. The old Line 8z / Line 24z offset still applies if you’re amending a 2022 or 2023 return.
How to Fill In Line 24z
Write a short description of the adjustment in the space next to Line 24z (“IRC 136 energy subsidy exclusion,” for example) and enter the dollar amount. If you have only one 24z item, that’s it.
With more than one 24z adjustment, prepare a separate statement listing each item and its calculated amount, attach it to your return, and enter only the combined total on the line itself. There’s no required IRS form number for the statement; it just needs to identify each adjustment clearly enough that an examiner can trace the math.
Even with a single entry, attach the supporting statement. A write-in adjustment without an explanation is the kind of thing an examiner flags for correspondence, which delays a refund and creates extra work. The attachment costs nothing and heads off the most common processing holdup.
Records to Keep and Penalty Exposure
Hold onto records supporting a 24z adjustment for at least three years from the later of the filing date or the return’s due date, matching the general assessment statute of limitations. If the adjustment relates to property basis, keep those records for as long as you own the property plus three years after you dispose of it.
Getting a 24z adjustment wrong can trigger the accuracy-related penalty under IRC Section 6662, which adds 20% to any underpayment caused by negligence or a substantial understatement. The penalty applies when the IRS finds you lacked a reasonable basis for the deduction. For uncommon adjustments, your defense is a paper trail: the calculation, the statutory authority, and documents proving the amount.
Because 24z entries are unusual by definition, they draw more scrutiny than adjustments on named lines. If your item fits a named line, use the named line. If it genuinely doesn’t, document it thoroughly before you file.