If you hold an interest in a partnership, an S corporation, or certain trusts and estates, a Schedule K-1 probably shows up in your mailbox every spring. It is one of the more confusing tax documents clients receive, partly because it reports your share of income, loss, deductions, and credits rather than cash you actually took home, and partly because it does not tell you outright whether that income is "nonpassive" or "passive." That distinction is left to you (and your tax preparer) to work out, and it has real consequences for what you can do with losses and how much tax you owe.
This article walks through how the passive versus nonpassive distinction works, why it matters, and some of the planning angles worth discussing with your CPA and your advisor. It is educational in nature and not a substitute for personalized tax advice.
Key takeaways
- A K-1 reports your allocated share of entity income. It does not by itself classify that income as passive or nonpassive.
- The classification generally depends on the underlying activity and whether you materially participated in it.
- Passive losses generally can only offset passive income, not wages or nonpassive business income. Disallowed losses carry forward.
- Rental activities are generally treated as passive, even if you are involved, unless a specific exception applies.
- The 3.8% Net Investment Income Tax generally applies to passive and portfolio income, but generally not to income from a trade or business in which you materially participate.
What a Schedule K-1 actually is
A Schedule K-1 is an informational form issued by a pass-through entity, a partnership, an S corporation, or a trust or estate, to report each owner's or beneficiary's share of that entity's income, deductions, and credits for the year. You receive one if you are a partner in a partnership, a member of an LLC taxed as a partnership, a shareholder in an S corporation, or a beneficiary of certain trusts and estates.
An important and often misunderstood point: the K-1 reports your allocated share of taxable income, which is not necessarily the same as cash you received. It is possible to owe tax on K-1 income even when the entity made no distribution to you that year, a situation sometimes informally called phantom income. Reviewing your K-1 alongside the entity's distribution history is a useful habit.
Passive versus nonpassive income, in plain terms
For federal tax purposes, the more precise distinction the IRS uses is passive versus nonpassive, rather than a single universal "active income" category. The classification generally comes down to two questions:
- What kind of activity generated the income, trade or business, rental, or portfolio?
- Did you materially participate in that activity?
Nonpassive business income generally results when you materially participate in a trade or business. Passive income or loss generally results when you do not materially participate in that trade or business. Material participation and passive activity rules are explained in IRS Publication 925.
Rental activities are treated differently. Rental real estate is generally considered passive regardless of how involved you are, with limited exceptions, including rules for taxpayers who qualify as real estate professionals and materially participate in the rental activity, as described in Publication 925.
Portfolio income sits in its own category. Interest, dividends, and many capital gains are generally treated as portfolio income, not as passive activity income, even though they may appear on a K-1 alongside passive or nonpassive business items.
How the K-1 itself reflects this
When a partnership or S corporation has more than one activity, the K-1 instructions generally call for an attached statement identifying each activity, trade or business, rental real estate, other rental, or portfolio, and allocating the related income, loss, deductions, and credits to each one. The draft 2026 Form 1065 Schedule K-1 includes a checkbox for "more than one activity for passive activity purposes," a signal that the entity expects you to apply the material participation tests separately to each listed activity rather than treating the whole K-1 as one undifferentiated item.
In practice, this means reviewing every box, footnote, and attached statement on your K-1, not just the summary numbers, to understand how each piece should be classified.
The material participation tests, generally
The IRS evaluates material participation using a set of tests built around your level of involvement in an activity, generally centered on the hours you devote to it and the nature of that involvement relative to others in the activity. These tests are detailed in IRS Publication 925 and are applied activity by activity, not entity by entity. Because the determination is fact specific and can depend on contemporaneous records, this is an area where working directly with your CPA or tax preparer matters, particularly if you hold interests in multiple ventures with varying levels of involvement.
Why the distinction matters
Passive activity loss (PAL) limitations. Losses from passive activities can generally only offset income from other passive activities, not wages, portfolio income, or income from a business in which you materially participate. Losses that cannot be used in the current year are generally suspended and carried forward, available to offset passive income in future years or, in many cases, when you dispose of your entire interest in the activity in a fully taxable transaction.
There are narrower exceptions worth knowing about in general terms: taxpayers who qualify as real estate professionals and materially participate in their rental real estate may be able to treat that rental income or loss as nonpassive, and certain taxpayers who actively participate in rental real estate may be eligible for a limited allowance, often referenced around a $25,000 threshold, subject to income phase-outs. The specifics of these exceptions are detailed enough that they should be reviewed with your tax professional rather than assumed.
The Net Investment Income Tax (NIIT). A 3.8% surtax generally applies to net investment income for taxpayers above certain income thresholds. Passive activity income and portfolio income are generally included in this calculation, while income from a trade or business in which you materially participate is generally excluded. This is one of the more consequential reasons the passive versus nonpassive distinction matters: the same dollar of K-1 income can be subject to NIIT or not, depending entirely on your participation in the underlying activity.
Planning angles worth discussing with your team
- Grouping activities. In some circumstances, taxpayers may be permitted to group certain interrelated activities together for purposes of the material participation tests, which can affect whether the combined activity is treated as passive or nonpassive. This is a technical area with specific rules and should be evaluated with your CPA.
- Tracking participation. Because material participation is based on facts like hours worked and the nature of your involvement, keeping contemporaneous records, calendars, logs, meeting notes, is far more useful than attempting to reconstruct participation after the fact.
- Timing dispositions. Because suspended passive losses can generally be freed up when you dispose of your entire interest in a passive activity in a fully taxable transaction, the timing of a sale or exit from a partnership or LLC interest can be a meaningful planning lever.
- Coordinating with the broader plan. K-1 income does not exist in isolation. How it is classified affects your total tax picture, your exposure to NIIT, and how your overall portfolio and tax strategy should be coordinated across the year, which is why K-1 review is often most useful as part of a broader planning conversation rather than a standalone tax exercise.
When to talk with us
Every household's mix of K-1 activities, participation levels, and overall tax picture is different. If you are receiving K-1s from partnerships, S corporations, real estate syndications, or other pass-through investments and want help thinking through how they fit into your broader financial plan, our team can work alongside your CPA or tax professional to look at the full picture.
Frequently asked questions
Does receiving a K-1 automatically mean my income is passive? No. The K-1 reports your allocated share of the entity's income, loss, deductions, and credits. Whether an item is passive or nonpassive depends on the type of activity and your level of participation, not simply the fact that it came from a pass-through entity.
Why did I owe tax on K-1 income I never received as cash? Because a K-1 reports your distributive share of taxable income, not necessarily cash distributed to you. An entity can allocate taxable income to you in a year when it makes no distribution, sometimes called phantom income.
Is rental real estate income always passive? Generally, yes, even if you are involved in managing the property, unless you qualify under specific exceptions such as the real estate professional rules or a limited active participation allowance. These exceptions have detailed requirements and should be reviewed with your tax professional.
How does the passive versus nonpassive distinction affect the Net Investment Income Tax? The 3.8% NIIT generally applies to passive activity income and portfolio income for taxpayers above certain income thresholds, but generally not to income from a trade or business in which you materially participate.
What happens to a passive loss I cannot use this year? It is generally suspended and carried forward to future years, available to offset passive income later or, in many cases, to be used when you dispose of your entire interest in the activity in a fully taxable transaction.
Can I combine several business activities to help meet the material participation test? In certain circumstances, activities may be grouped for this purpose, but the rules are technical and should be evaluated carefully with your CPA rather than assumed.