Schedule K-1 (Form 1120-S): How S-Corp Income Reaches Your 1040

Two friends start consulting businesses the same year with nearly identical profit. One forms a multi-member LLC with a partner. The other elects S-Corp status. The following March, both open an envelope with a tax form inside, both see roughly the same number in the income box, and both assume their tax bills will match. They will not. The form is a Schedule K-1, and the gap between an S-Corp K-1 and a partnership K-1 is worth thousands of dollars a year. The owners below are theoretical, not actual EntityIQ clients.

What a Schedule K-1 actually is

An S-Corp does not pay federal income tax at the entity level. It files Form 1120-S, an informational return, and passes its income, deductions, and credits through to the shareholders under IRC §1366. Each shareholder receives a Schedule K-1 (Form 1120-S) that reports their pro rata share of each item. You copy those figures onto your Form 1040 and pay tax at your individual rates. The corporation itself writes almost no check to the IRS.

One point trips up almost every new S-Corp owner. You pay tax on your share of the profit whether or not the company actually distributes the cash to you. If your S-Corp earns $100,000 and you leave it all in the business bank account, you still report and pay tax on your full share under the pass-through rules of §1366. The distribution is a separate event, and it is not what triggers the income tax.

The three boxes that matter

Most of a K-1 sits blank for a simple single-owner S-Corp. Three entries carry the weight.

Box 1 is ordinary business income. This is your share of the company's profit after your W-2 wages have already been deducted. It flows to Part II of Schedule E on your Form 1040, and from there into your taxable income.

Box 16, code D is distributions. This is the cash the company actually paid you during the year. It is not a second layer of income tax. Distributions reduce your stock basis under IRC §1368, and as long as they stay within your basis, they come out tax-free because the underlying profit was already taxed to you through box 1.

Box 17, code V is the Section 199A information. The S-Corp attaches a Statement A that breaks out your qualified business income, W-2 wages, and the other figures your preparer needs to compute the §199A qualified business income deduction, which can shave up to 20% off the business income that lands on your return. For how that deduction is figured, see our QBI deduction guide.

Why the S-Corp K-1 beats the partnership K-1

Here is where the entity choice turns into real dollars. On a partnership return, Form 1065, a general partner or an active member of a multi-member LLC generally pays self-employment tax on their full distributive share of the business profit. That share shows up in box 14, code A of the partnership K-1 and runs through Schedule SE at 15.3% up to the Social Security wage base, which is $184,500 for 2026, under IRC §1402(a).

An S-Corp K-1 works differently, because the ordinary business income in box 1 is not self-employment income at all. The IRS confirmed this in Rev. Rul. 59-221, and the courts have upheld it since. The only earnings the S-Corp owner pays payroll tax on are the W-2 wages the company is required to pay for the owner's services. Distributions and box 1 income carry no self-employment or FICA tax. That single difference is the entire reason the S-Corp election exists.

The catch is that you cannot zero out the wages to make all of the profit escape payroll tax. The IRS requires an owner who works in the business to take reasonable compensation, and under Rev. Rul. 74-44 it will recharacterize distributions as wages when a shareholder is paid distributions in lieu of a salary. Set the salary at a defensible level, and the rest of the profit flows through the K-1 free of the 15.3% hit.

Same profit, two K-1s

Consider two theoretical owners, each with $160,000 of business profit and no other job. One runs a multi-member LLC taxed as a partnership. The other elected S-Corp status and pays a $75,000 reasonable salary. Numbers use 2026 figures and are rounded.

The partnership owner's entire $160,000 share runs through self-employment tax. On 92.35% of that profit at 15.3%, the bill is about $22,607, with the 92.35% multiplier set by IRC §1402(a)(12). The S-Corp owner pays regular FICA on the $75,000 salary, about $11,475, and the $85,000 that flows through box 1 of the K-1 carries no payroll tax. The payroll-tax savings come to roughly $11,100 before costs. After payroll processing, the 1120-S, and any state fees, I would expect this owner to keep somewhere around $8,000 to $9,000, every year the profit holds.

What flows where on your 1040

When you hand the K-1 to a preparer, box 1 lands on Schedule E, your distributions are measured against your stock basis on Form 7203, and the Section 199A statement drives the qualified business income deduction. If the company passed through a loss instead of a profit, you can deduct it only to the extent of your basis under IRC §1366(d). Anything beyond your basis carries forward until you have basis to absorb it. That is why tracking basis matters, and why the IRS now requires Form 7203 with your return when you claim a loss, receive a distribution, or dispose of stock. Our guide on S-Corp stock basis and Form 7203 walks through the running total.

If you are weighing a multi-member LLC against an S-Corp, the K-1 is where the two paths split. Run your own numbers through the EntityIQ S-Corp tax calculator before you decide, and read our guides on S-Corp reasonable compensation and how S-Corp distributions are taxed for the pieces that sit on either side of box 1.

This article is educational and is not legal or tax advice. The numbers above are 2026 figures, and the owners are theoretical. Please consult a qualified CPA before filing an S-Corp election or your return.