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Schedule K-1 Explained: What It Is and How to Read It

By The Ledgerism Editorial Team · The Ledgerism Brief Editorial Team produces original, methodology-disclosed accounting and tax research—data trackers, databases, and reference guides built to be the most-cited source in the field. Every figure is verified against primary sources including FASB, the IRS, the PCAOB, NASBA, the AICPA, and state boards of accountancy.

A Schedule K-1 is the IRS form that reports your share of income, deductions, and credits from a pass-through entity you own or benefit from. The entity itself usually pays no federal income tax. Instead the profit or loss flows to you, and the K-1 tells you the dollar amounts and codes to copy onto your Form 1040. You get one if you are a partner in a partnership, a shareholder in an S corporation, or a beneficiary of an estate or trust.

There are three versions, tied to three different business returns: Form 1065 (partnerships), Form 1120-S (S corporations), and Form 1041 (estates and trusts). They share a three-part layout but differ in who prepares them, how income is allocated, and how the numbers hit your personal return. This guide reads the form box by box and shows where each figure goes.

What is a Schedule K-1?

A Schedule K-1 is an information return that reports one owner’s or beneficiary’s share of a pass-through entity’s tax items for the year. It is not a tax you pay to the entity. The entity files a business return, splits each line among the owners, and issues each owner a K-1 so they can report their slice on their own Form 1040. The IRS receives a copy and matches it against your return.

Pass-through treatment means income is taxed once, at the owner level, not at the entity level. A partnership or S corporation with $500,000 of ordinary income pays no federal income tax itself. That $500,000 is divided across the K-1s and taxed on the owners’ individual returns at their own rates. This is the mechanism behind the pass-through economy, where most U.S. business income now leaves the corporate form.

You do not file the K-1 with your return the way you attach a W-2. You use the numbers on it to complete schedules such as Schedule E, Schedule B, Schedule D, and Form 4797, and you keep the K-1 for your records. The issuing entity is the party that transmits copies to the IRS.

The three types of Schedule K-1

The three K-1 versions differ by the entity that issues them, the return they attach to, how items are allocated, and whether the income can carry self-employment tax. The table below summarizes the differences. All three use the same Part I, Part II, Part III structure, so once you can read one, the others follow.

The partnership K-1 is the most flexible. Partnership agreements can allocate profit, loss, and specific items differently from raw capital percentages, as long as the allocation has substantial economic effect under IRC Section 704(b). General partners often owe self-employment tax on Box 1 ordinary income.

The S corporation K-1 is the most rigid. Items are allocated strictly by ownership on a per-share, per-day basis under IRC Section 1377, unless the corporation makes a closing-of-the-books election. S corporation pass-through income generally escapes self-employment tax, which is why the IRS requires shareholder-employees to take a reasonable salary reported on a W-2 before taking distributions.

The estate and trust K-1 reports amounts the fiduciary distributed to a beneficiary, capped at the entity’s distributable net income (DNI). The trust or estate deducts what it distributes, so the same dollars are taxed once, on the beneficiary’s return, and retain their character (interest stays interest, capital gain stays capital gain).

How to read a Schedule K-1

Every K-1 has three parts: Part I identifies the entity, Part II identifies you, and Part III lists your share of the tax items. The dollars you actually report live in Part III, where numbered boxes each carry an amount and sometimes a letter code that tells you the type of item and where it belongs on your return.

Part I: information about the entity

Part I names the pass-through entity, its employer identification number (EIN), address, and the IRS service center where it filed. On the 1065 and 1120-S versions it also flags whether the entity is publicly traded, which changes how passive losses are handled. Confirm the EIN matches other correspondence, because a mismatch is a common source of IRS matching notices.

This section rarely affects your math directly. Its job is to link your Part III numbers to a specific return the IRS already has on file. If you invest in a publicly traded partnership, the Part I checkbox for a PTP signals that your losses are suspended and usable only against income from that same PTP.

Part II: information about you

Part II shows your name, taxpayer identification number, and your ownership stake. On a partnership K-1 it reports your profit, loss, and capital percentages at the beginning and end of the year, plus a capital account rollforward reported on the tax basis method. On an S corporation K-1 it reports your stock ownership percentage for the year.

Your ownership percentages here drive the numbers in Part III, so check them against your partnership agreement or stock ledger. Partnership Item L (the capital account) and the S corporation basis figures feed your basis tracking, which controls how much loss you can actually deduct. S corporation shareholders track this on Form 7203 for stock and debt basis.

Part III: your share of income, deductions, and credits

Part III is the working section, with boxes numbered 1 through roughly 20 to 23 depending on the version. Each box reports one category of item, and many boxes carry a letter code (for example, Box 13 or Box 17 codes) that points to a specific line or form. The K-1 instructions include a full code key you use to translate each code.

Common Part III boxes and where they typically go on a Form 1040 include:

1. Ordinary business income or loss (Box 1): Schedule E, Part II. General partners may also owe self-employment tax via Schedule SE.
2. Net rental real estate income (Box 2 on 1065, Box 2 on 1120-S): Schedule E, Part I or II, subject to passive activity rules.
3. Interest income: Schedule B, then Form 1040 line 2b.
4. Ordinary and qualified dividends: Schedule B and Form 1040 lines 3a and 3b.
5. Net Section 1231 gain: Form 4797, then Schedule D if treated as capital gain.
6. Section 199A information (Box 20 code Z on 1065, Box 17 code V on 1120-S): supports the Section 199A qualified business income deduction on Form 8995 or 8995-A.

Do not report a Box 1 loss automatically. Losses are limited by your basis, the at-risk rules under IRC Section 465, and the passive activity rules under IRC Section 469. A loss that exceeds your basis is suspended and carried forward, not deducted this year.

Common K-1 problems and how to handle them

The most frequent K-1 issues are late delivery, deducting losses you have no basis for, and mismatched EINs or amounts that trigger IRS notices. Most are avoidable if you reconcile the K-1 against your basis records and the entity’s return before you file, and if you build in time for K-1s that arrive close to or after the April deadline.

Late K-1s are common because partnership and S corporation returns are due March 15 (March 16 in 2026) and estate and trust returns April 15, often the same window as your own return. If an entity extends to September 15, you generally extend your Form 1040 with Form 4868 and wait, rather than guessing at the numbers. Filing without a K-1 you know is coming invites an amended return.

Basis is the second trap. You cannot deduct partnership or S corporation losses beyond your basis in the entity. S corporation shareholders must attach Form 7203 when they deduct a loss, receive a distribution, or dispose of stock. If you are weighing which entity fits your situation, the business entity comparison lays out how LLC, S-corp, C-corp, and partnership taxation differ.

Frequently asked questions

What is a Schedule K-1 used for?

A Schedule K-1 reports your share of a pass-through entity’s income, deductions, and credits so you can report them on your own tax return. Partnerships (Form 1065), S corporations (Form 1120-S), and estates and trusts (Form 1041) issue K-1s. The entity generally pays no federal income tax; the tax items flow through to owners or beneficiaries and are taxed once, on their individual returns.

When should I receive my K-1?

Calendar-year partnerships and S corporations must furnish K-1s by their return due date, generally March 15 (March 16 in 2026 because the 15th is a Sunday). Estates and trusts must furnish K-1s by April 15. If the entity files Form 7004 for an extension, the K-1 can arrive as late as September 15 for partnerships and S corporations, or September 30 for estates and trusts.

Do I pay tax on the K-1 or does the business?

In most cases you pay the tax, not the business. Partnerships, S corporations, and most trusts are pass-through entities, so income is taxed once at the owner or beneficiary level rather than at the entity level. You report the K-1 amounts on your Form 1040 at your own rates. Some states impose entity-level taxes or elective pass-through entity taxes that change this at the state level.

Is K-1 income subject to self-employment tax?

It depends on the entity and your role. General partners often owe self-employment tax on Box 1 ordinary business income from a Form 1065 K-1. S corporation pass-through income on a Form 1120-S K-1 is generally not subject to self-employment tax, which is why shareholder-employees must take a reasonable W-2 salary first. Beneficiary income on a Form 1041 K-1 is generally not self-employment income.

Where do I report Schedule K-1 income on my 1040?

It depends on the box. Ordinary business income (Box 1) usually goes on Schedule E, Part II. Rental income (Box 2) goes on Schedule E. Interest and dividends go on Schedule B and Form 1040 lines 2b, 3a, and 3b. Section 1231 gains go on Form 4797. Each Part III box and code maps to a specific line, listed in the IRS K-1 instructions.

What if my K-1 shows a loss?

A loss on your K-1 is not automatically deductible. Partnership and S corporation losses are limited by your basis in the entity, the at-risk rules under IRC Section 465, and the passive activity loss rules under IRC Section 469. A loss that exceeds your basis or your at-risk amount is suspended and carried forward to a future year when you have basis or offsetting income.

Can I file my taxes before I get my K-1?

Generally no, if you know a K-1 is coming. Filing without it risks an IRS matching notice and an amended return once the correct numbers arrive. If the issuing entity has extended its return, file Form 4868 to extend your own Form 1040 and pay any estimated tax due by the April deadline to limit interest and penalties, then file once the K-1 is in hand.

Reviewed by The Ledgerism Editorial Team. Last reviewed: July 2026.

Related guides

• Schedule 1 (Form 1040)
• How to Fill Out a W-9 (2026)
• How to Fill Out a W-4 (2026)
• The W-2 Form Explained
• Form 2848 (Power of Attorney)
• Form 7004