Schedule K-1 for Partnerships: Loss Limits, QBI, and Filing

A Schedule K-1 for partnerships reports your individual share of a partnership’s income, deductions, and credits for the year, and those amounts flow onto your personal tax return where they are taxed at your individual rates whether or not the partnership actually distributed any cash to you.¹ The partnership itself pays no federal income tax; you do. Reading the form correctly, tracking the limits on what you can deduct, and knowing where each box lands on your return is what keeps a K-1 from turning into a tax bill you did not see coming.

What Each Part of the Form Reports

Federal law requires every partnership to file a return and give each partner a statement of their share of the year’s financial activity.² The K-1 has three parts.

Part I identifies the partnership by employer identification number, name, and address. Part II identifies you: your Social Security number or taxpayer identification number, your address, and your ending percentage share of profits, losses, and capital.³ Those percentages determine your proportional slice of everything the partnership earned and spent.

Part III is where the money is. Numbered boxes split the partnership’s activity into categories: ordinary business income in Box 1, rental real estate income in Box 2, interest income in Box 5, dividends in Box 6, capital gains and losses in Boxes 8 through 10, and more.³ Each category is treated differently on your personal return, which is why the form separates them rather than handing you a single total.

Guaranteed Payments

If the partnership pays you a fixed amount for services or for the use of your capital regardless of whether the business made money, those are guaranteed payments, reported in Boxes 4a through 4c.³ They function like a partnership salary: the partnership deducts them, and you report them as ordinary income.⁴

No taxes are withheld from a guaranteed payment. That means quarterly estimated tax payments are on you, and skipping them triggers underpayment penalties at filing.

Self-Employment Tax

Whether your K-1 income owes self-employment tax depends on your role in the business. General partners owe self-employment tax on their distributive share of the partnership’s trade or business income plus any guaranteed payments for services. That tax covers Social Security and Medicare on top of regular income tax.⁵

Limited partners generally do not owe self-employment tax on their distributive share. The exception: guaranteed payments for services are always subject to self-employment tax, even for a limited partner.⁵ The K-1 reports your self-employment earnings in Box 14, and that figure carries onto Schedule SE with your personal return.⁶

Passive Versus Nonpassive Income

The IRS treats income very differently depending on whether you actively work in the business or just invest in it. Passive income comes from activities where you do not materially participate. Rental real estate is the classic example, but any partnership business where you are not regularly and substantially involved qualifies. The rule to remember: passive losses can only offset passive income. A $50,000 passive loss with no passive income to absorb it is suspended and carries forward until you either generate passive income or dispose of your entire interest in the activity.⁷

Nonpassive income comes from businesses where you materially participate. The most commonly used test is more than 500 hours in the activity during the tax year, though the IRS recognizes several alternative tests.⁸ Nonpassive losses are more valuable because they can offset wages, interest, and other ordinary income. If the IRS later recharacterizes what you claimed as nonpassive, deductions you already took can be disallowed, and you will owe back taxes and interest.

The Loss Limitation Waterfall

Partnership losses do not flow straight through unchecked. They pass through a sequence of filters, and each can cap what you deduct.

Basis Limitation

Basis is your tax investment in the partnership, and it caps your deductible losses. If the partnership allocates you $80,000 in losses but your basis is $50,000, you deduct $50,000 and carry the rest forward.⁹

Basis starts with your initial contribution and moves from there. It goes up when you contribute more, when income is allocated to you, or when your share of partnership debt increases. It goes down when the partnership distributes cash to you, allocates losses, or your share of debt decreases. The capital account section of the K-1 supplies the data points, but tracking basis is your job, not the partnership’s.

One trap: a cash distribution that exceeds your basis triggers capital gains tax on the excess in the year of the distribution. Partners who do not track basis sometimes learn about the tax after the money is already spent.

At-Risk Limitation

A loss that clears basis still has to clear the at-risk rule. Your at-risk amount is generally the cash and property you contributed plus partnership debt for which you are personally liable. Nonrecourse loans where no one is personally on the hook, along with amounts protected by guarantees or stop-loss arrangements, do not count.¹⁰ Blocked losses carry forward.

Passive Activity Limitation

Losses that pass basis and at-risk still face the passive activity gate if the activity is passive. Passive losses only offset passive income.⁷ Suspended passive losses stack up and release in full when you sell your entire interest in the activity in a taxable transaction.

Excess Business Loss Limitation

Nonpassive losses that survive every prior filter face one more cap. For 2026, aggregate business losses above $256,000 for single filers or $512,000 for joint filers are treated as a net operating loss carried to the next year rather than deducted in full on the current return. This limit applies after netting all business income and losses across all activities.

The Section 199A Deduction

Partners may qualify to deduct up to 20% of their qualified business income from the partnership. The calculation happens on your personal return, but the partnership supplies the inputs in Box 20, Code Z of the K-1.¹¹

The deduction is the lesser of 20% of your qualified business income or 20% of your taxable income minus net capital gains. Above certain income thresholds, additional limits kick in based on the W-2 wages the partnership paid and the cost of its depreciable property. Your partnership should attach a supplemental statement with the detailed breakdowns needed to run those calculations.⁶ Thresholds are indexed annually for inflation.

Specified service trades and businesses, including law, medicine, accounting, and consulting, face tighter treatment. Above the income thresholds, the deduction for these fields phases out entirely. Below the thresholds, they qualify the same as any other business.

Net Investment Income Tax

Some partnership income also carries an additional 3.8% Net Investment Income Tax if your modified adjusted gross income exceeds $200,000 (single) or $250,000 (married filing jointly).¹² Those thresholds are not indexed for inflation, so more partners cross them each year.

The partnership reports the relevant information in Box 20, Code Y. Investment income from a partnership typically includes interest, dividends, capital gains, rental income, and income from businesses in which you do not materially participate. If you materially participate in the partnership’s trade or business, that ordinary income is generally not net investment income. Gain from selling your partnership interest can also trigger the tax.⁶ The calculation goes on Form 8960 with your personal return.

Where the Numbers Land on Your Return

Most K-1 items land on Schedule E (Form 1040). Ordinary business income from Box 1 goes to Schedule E, line 28. Rental income from Box 2 goes to the same area but in the passive column. Guaranteed payments from Box 4 report as ordinary income on Schedule E. Royalties from Box 7 go to Schedule E, line 4.⁶

Capital gains and losses from Boxes 8 through 10 flow to Schedule D and Form 8949. Self-employment earnings from Box 14 go to Schedule SE. Interest and dividend income may need to appear on Schedule B. Tax software routes most of this automatically once the K-1 is entered, but knowing the destination helps you catch errors.

After filing, the IRS matches your return against the partnership’s Form 1065. Discrepancies produce notices. The matching is automated and efficient, and small mismatches are enough to trigger one.

Schedule K-3 for International Items

If the partnership has foreign operations, foreign-source income, or other international tax items, you may also receive a Schedule K-3 alongside your K-1. It is an extension of the K-1 that provides the detail you need to claim foreign tax credits, report foreign-source income, and handle other international obligations.¹³

Not every partnership issues a K-3. If you need the international information and did not receive one, you can request it, and the partnership must provide it within one month of the request.¹³

When the K-1 Is Wrong

If you believe the K-1 misstates your share of income or deductions, ask the partnership for a corrected form first. If the partnership will not fix it and you report different amounts on your personal return, you must file Form 8082 to notify the IRS that you are treating items inconsistently with what was reported.¹⁴ Deviating from the K-1 without Form 8082 is a common mistake that can trigger automatic penalties.

Under the Bipartisan Budget Act rules, partnership-level corrections happen through an administrative adjustment request rather than an amended return. If that occurs, the partnership sends you Form 8986 showing your share of the adjustments, and you use Form 8978 to figure and report the tax impact on your return for the year you receive the adjustment, not the year the error originally occurred.¹⁵

Filing Deadlines

Calendar-year partnerships must file Form 1065 and deliver K-1s by March 15.¹⁶ Fiscal-year partnerships file by the 15th day of the third month after their tax year ends. The early deadline exists so partners have K-1s in hand before the April 15 individual filing date.

Partnerships can request an automatic six-month extension by filing Form 7004 before the original due date.¹⁷ That pushes the K-1 deadline to September 15 for calendar-year partnerships. If your partnership extends, you will almost certainly need Form 4868 to extend your personal return as well. An extension to file is not an extension to pay: any tax expected on the partnership income is still due by April 15, and interest accrues on any shortfall from that date.

1
Internal Revenue Service. Partner’s Instructions for Schedule K-1 (Form 1065)
2
Office of the Law Revision Counsel. 26 USC 6031 – Return of Partnership Income
3
Internal Revenue Service. Schedule K-1 (Form 1065) – Partner’s Share of Income, Deductions, Credits, etc.
4
Internal Revenue Service. Publication 541, Partnerships
5
Office of the Law Revision Counsel. 26 USC 1402 – Definitions
6
Internal Revenue Service. Partner’s Instructions for Schedule K-1 (Form 1065)
7
Office of the Law Revision Counsel. 26 USC 469 – Passive Activity Losses and Credits Limited
8
Internal Revenue Service. Publication 925 – Passive Activity and At-Risk Rules
9
Office of the Law Revision Counsel. 26 USC 704 – Partner’s Distributive Share
10
Office of the Law Revision Counsel. 26 USC 465 – Deductions Limited to Amount at Risk
11
Office of the Law Revision Counsel. 26 USC 199A – Qualified Business Income
12
Internal Revenue Service. Instructions for Form 8960
13
Internal Revenue Service. Partnership Instructions for Schedules K-2 and K-3 (Form 1065)
14
Internal Revenue Service. About Form 8082, Notice of Inconsistent Treatment or Administrative Adjustment Request (AAR)
15
Internal Revenue Service. File an Administrative Adjustment Request for a BBA Partnership
16
Office of the Law Revision Counsel. 26 USC 6072 – Time for Filing Income Tax Returns
17
Internal Revenue Service. Instructions for Form 7004