IRS Form 1040 Schedule 1: Additional Income & Adjustments — The Operator's Playbook
Form 1040 is a summary page with room for wages, interest, and dividends — and then it stops. Everything else a taxpayer earns, and every adjustment that lowers income before the standard deduction, lives on Schedule 1. If your return has a side business, unemployment, gambling winnings, a state refund, an HSA, or an IRA, Schedule 1 is where it is decided. This playbook runs it line by line for 2026.
One dating note first. Line structure follows the 2025 Schedule 1 form and instructions, current when researched on November 6, 2026; the 2026 form was not yet posted, so all 2026 dollars come from Rev. Proc. 2025-32, Rev. Proc. 2025-19, IR-2025-107, IR-2025-111, and the December 2026 instructions.
Who this is for — and who should stop here
This guide is for the filer whose income does not fit on the face of Form 1040: the freelancer with Schedule C profit, the landlord with Schedule E income, the worker who collected unemployment, the teacher buying classroom supplies. It is also for the preparer explaining a $4,500 casino win that raised a client's tax when they lost $3,000 the same night.
Stop here if your return is wages and bank interest only — you do not file Schedule 1. Get professional help for a net operating loss carryforward, a § 461(l) excess business loss, foreign earned income, or cancellation of debt tied to bankruptcy or insolvency: the elections are easy to get wrong and expensive to fix.
Schedule 1 carries the same identification as Form 1040: your Social Security number (SSN), or an Individual Taxpayer Identification Number (ITIN) if you are not eligible for an SSN. A sole proprietor reports on Schedule C under the owner's SSN; a partnership or S corporation files under its own Employer Identification Number (EIN) and passes its result on a Schedule K-1 to line 5. An LLC is not a tax classification: a single-member LLC reports on Schedule C, an LLC electing S-Corp treatment passes income through on a K-1, and a C-Corp pays its own tax. Employees pay FICA tax through withholding; the self-employed pay SECA tax on Schedule SE, and half of that tax is line 15. These are tax-basis numbers, not GAAP — a CPA prepares the return, but the taxpayer signs it.
The authority frame: what Schedule 1 does to AGI
26 U.S.C. § 62(a) defines adjusted gross income as gross income minus the listed deductions, and Schedule 1 is the worksheet: Part I adds income the face of Form 1040 has no room for; Part II subtracts the § 62 adjustments:
$
\text{AGI} = \text{Form 1040 line 9} - \text{Schedule 1 line 26}, \quad \text{Form 1040 line 8} = \text{Schedule 1 line 10}
$
Line 10 goes to Form 1040 line 8; line 26 to line 10. AGI on line 11 is line 9 minus line 10, and everything downstream keys off AGI — standard deduction, taxable income, tax table, most credits, the IRA and student-loan phase-outs. An error here reprices the whole return.
> [!KEY TAKEAWAY]
> Schedule 1 is the bridge to adjusted gross income, the number the rest of the return is computed from. Get lines 10 and 26 right.
Part I: additional income, lines 1–9
Most Part I lines are pass-throughs from another schedule.
| Line | What lands here |
| --- | --- |
| 1 | State/local tax refunds |
| 2a | Alimony, pre-2019 agreements |
| 3 | Business income or loss (Schedule C) |
| 4 | Other gains/losses (4797/4684) |
| 5 | Rental/royalties/partnerships/S corps |
| 6 | Farm income or loss |
| 7 | Unemployment compensation |
| 8a–8z | Other income (26 sub-lines) |
| 10 | Total additional income |
Line 1: a state refund is taxable only if you itemized in the year you paid the tax; if you took the standard deduction, or deducted state sales taxes, none of it is taxable. Line 2a is narrower than expected: alimony counts only for agreements executed on or before December 31, 2018, unless later changed to expressly exclude it. Under a later agreement it is not income — the same cutoff governs line 19a.
Schedule C profit or loss flows to line 3 (Schedule C playbook). Rental, royalty, partnership, and S corporation income arrive from Schedule E on line 5 (Schedule E playbook). Capital gains do not appear here — they go through Schedule D (Schedule D playbook); only Form 4797 and Form 4684 gains land on line 4.
Unemployment compensation is fully taxable ordinary income; the code has no exclusion for it. Repaying an overpayment during the year reduces line 7.
Line 8 is the catch-all: 8a net operating loss (negative); 8b gambling winnings in full — losses go on Schedule A if you itemize; 8c cancellation of debt; 8i prizes and awards; 8m Olympic medals/USOC prizes; 8p the § 461(l) adjustment; 8z the residual. Line 9 totals 8a–8z; line 10 adds lines 1–7 and line 9.
> [!WARNING]
> Never net gambling losses against winnings on line 8b: the statute taxes gross winnings, and the loss deduction lives on Schedule A.
Where 1099-K and 1099-NEC amounts land
Two information returns cause most Schedule 1 routing errors, and both changed for 2026: a 1099-K reports payments settled through a third-party network, and a 1099-NEC reports nonemployee compensation. Neither decides whether the money is taxable — both only report that it was paid.
| Situation | 2026 reporting test | Where it lands | Authority |
| --- | --- | --- | --- |
| 1099-K, payment app/marketplace | Over $20,000 AND over 200 transactions | Schedule C or capital-gain reporting | IR-2025-107 |
| 1099-K, amount in error or personal items at a loss | No threshold | Top-of-form entry | Schedule 1 form |
| 1099-NEC, contractor work | $2,000 for 2026; $600 for 2025 | Schedule C, then Schedule 1 line 3 | Instructions, 12/2026 |
The One, Big, Beautiful Bill retroactively reinstated the pre-2021 test: a third-party settlement organization need not file unless reportable payments to a payee exceed $20,000 and transactions exceed 200, per platform, per year (IR-2025-107). A seller with $24,000 across 260 transactions gets a 1099-K; one with $25,000 across 150 does not. The threshold governs reporting, not taxability: amounts reported in error, or for personal items sold at a loss, go at the top of Schedule 1, out of income.
The 1099-NEC threshold moved the other way: the December 2026 instructions raise the minimum to $2,000 for tax years beginning after 2025, adjustable for inflation from 2027. A client who paid a contractor $1,500 in 2026 need not issue a 1099-NEC — but the contractor still reports it. The 1099-NEC playbook covers the payer side.
Part II: adjustments to income, lines 11–26
Part II is the valuable half. These adjustments reduce AGI dollar for dollar, help whether or not you itemize, and lower the AGI other phase-outs are measured against.
| Line | Adjustment | 2026 limit |
| --- | --- | --- |
| 11 | Educator expenses | $350 |
| 12 | Reservists/performers/fee-basis | Actual expenses |
| 13 | HSA | $4,400 self-only; $8,750 family |
| 14 | Moving, Armed Forces only | Actual expenses |
| 15 | Half of SE tax | One-half of SE tax |
| 16 | SEP/SIMPLE plans | Plan limits |
| 17 | SE health insurance | Premiums paid |
| 18 | Early-withdrawal penalty | Amount forfeited |
| 19a | Alimony paid, pre-2019 | Amount paid |
| 20 | IRA deduction | $7,500; $8,600 at 50+ |
| 21 | Student loan interest | $2,500 maximum |
| 26 | Total adjustments | Lines 11–23 + 25 |
Line 11 is capped at $350 for 2026 — books, supplies, and classroom materials for eligible educators. Line 13, the HSA deduction, is capped by Rev. Proc. 2025-19: $4,400 self-only and $8,750 family under a high deductible health plan, with minimum deductibles of $1,700 and $3,400 and out-of-pocket maximums of $8,500 and $17,000. Employer contributions count toward it.
Line 15 trips up self-employed filers most. Schedule SE multiplies net earnings by 92.35%, applies 12.4% Social Security tax up to the 2026 wage base of $184,500 and 2.9% Medicare tax, and its line 13 lands on Schedule 1 line 15. Section 164(f) allows exactly one-half of the § 1401 tax.
Line 20, the IRA deduction, for 2026 (IR-2025-111): the limit is $7,500, up from $7,000, plus $1,100 at 50 and over. Deductibility is separate: a single filer covered by a workplace plan phases out between $81,000 and $91,000 of modified AGI; a covered joint filer, between $129,000 and $149,000. No workplace plan means no income test. Line 21, student loan interest, caps at $2,500 and phases out above $85,000 single and $175,000 joint, ending at $100,000 and $205,000. At modified AGI of $92,500 with $2,400 of interest paid, a single filer keeps half:
$
\text{Allowable interest} = \$2{,}400 \times \left(1 - \frac{\$92{,}500 - \$85{,}000}{\$100{,}000 - \$85{,}000}\right) = \$2{,}400 \times 0.50 = \$1{,}200
$
> [!TIP]
> Run Part II before deciding whether to itemize: a lower AGI can restore part of a phased-out IRA or student-loan deduction.
The § 461(l) excess business loss limitation
Section 461(l) caps the business loss a noncorporate taxpayer can use in one year — which is why line 8p exists. Under § 461(l)(3), the excess business loss is aggregate trade-or-business deductions over aggregate trade-or-business gross income plus a threshold — $250,000 in the statute ($500,000 joint) — inflation-adjusted after 2025. Rev. Proc. 2025-32 sets the 2026 threshold at $256,000, or $512,000 for joint returns. The disallowed loss is not lost: § 461(l)(2) treats it as a net operating loss carryover. The limit applies after § 469, at the partner or shareholder level. The One, Big, Beautiful Bill made it permanent (Pub. L. 119–21 § 70601).
$
\text{Excess business loss} = \text{Business deductions} - (\text{Business gross income} + \text{\$256,000 threshold}) \quad \text{(single, 2026)}
$
Worked: a single filer has Schedule C gross income of $210,000 and deductions of $640,000 — a net loss of $430,000. The excess is $640,000 minus ($210,000 + $256,000), or $174,000, disallowed for 2026, entered on line 8p, and carried forward as a net operating loss. The loss allowed is $430,000 minus $174,000, or $256,000 — exactly the threshold.
Worked example: one return, start to finish
Maya, 34, single, with no workplace plan, earned $92,000 in wages, ran a side business, collected unemployment for two months, and won $4,500 at a casino while losing $3,000:
| Schedule 1 line | Item | Amount |
| --- | --- | --- |
| 1 | State tax refund | $1,800 |
| 3 | Schedule C income | $18,400 |
| 7 | Unemployment | $6,200 |
| 8b | Gambling winnings | $4,500 |
| 8i | Prizes and awards | $1,200 |
| 9 | Total other income | $5,700 |
| 10 | Additional income | $32,100 |
| 11 | Educator expenses | $350 |
| 13 | HSA deduction | $4,400 |
| 15 | SE tax, half | $1,300 |
| 20 | IRA deduction | $7,500 |
| 26 | Total adjustments | $13,550 |
Line 10: $1,800 + $18,400 + $6,200 + $5,700 = $32,100. Line 26: $350 + $4,400 + $1,300 + $7,500 = $13,550. Total income: $92,000 + $32,100 = $124,100. AGI: $124,100 − $13,550 = $110,550.
Schedule C profit is $18,400; Schedule SE multiplies by 92.35% for net earnings of $16,992.40, then applies 15.3% for tax of $2,599.84, rounded to $2,600. One-half is $1,300. Had she been covered by a workplace plan, her IRA deduction would be zero — her AGI exceeds the $81,000–$91,000 phase-out.
The 2026 single standard deduction is $16,100, so taxable income is $110,550 minus $16,100, or $94,450. Under the 2026 single tax table, the tax is $5,800 plus 22% of $44,050, or $15,491. Her $3,000 of gambling losses appear nowhere here: she takes the standard deduction, so she cannot itemize them; even itemizing, § 165(d) caps the deduction at 90%. Break-even is now taxable: $10,000 won against $10,000 lost leaves a $9,000 deduction and $1,000 of taxable winnings. Test a different income mix with the profit calculator.
> [!FOUNDER]
> "Schedule 1 is where a return stops being a summary and starts being a story. Wages tell you what someone was paid. This schedule tells you what they built, what they lost, what they set aside for health and retirement, and what the law lets them keep. Read it before you judge the return."
> — Enow A. Jovial, Founder & Chief Executive Officer
The five-step filing sequence
1. Gather every information return — W-2, 1099-NEC, 1099-K, 1099-G, 1099-R, K-1 — and match each to a Schedule 1 line first.
2. Complete Schedules C, D, E, and F before touching Schedule 1; lines 3, 5, and 6 are pass-throughs.
3. Enter Part I top to bottom, then add lines 9 and 10, re-adding by hand.
4. Enter Part II, then check each phase-out: IRA coverage, student-loan MAGI, the HSA ceiling.
5. Post lines 10 and 26 to Form 1040 lines 8 and 10 and verify the footings: total income minus adjustments equals AGI, and AGI minus the standard deduction equals taxable income.
Execution checklist
What Schedule 1 cannot do
Schedule 1 cannot fix a missing information return, or convert a nondeductible item into a deduction by relabelling it. Gambling losses stay on Schedule A. A state refund stays nontaxable only if you did not itemize the year you paid the tax. A civilian move is not deductible. The schedule's totals are only as honest as the source schedules: a Schedule C with invented expenses produces a line 3 no Schedule 1 arithmetic can rescue. According to IRS statutory guidelines, the return is a single document, and Schedule 1 is where the filer proves they understand what they earned and what the law allows them to subtract.