How Is K-1 Income Taxed? A Guide for High-Income W-2 Families

By Kevin Luu, Co-Founder and Chief Learning Officer. Reviewed on 2026-09-30.

K-1 income is taxed on your personal return, at your own rates, not at the partnership, S corporation or trust that sends the form. Each line keeps its character: ordinary business income and interest are taxed like wages, while qualified dividends and long-term capital gains get the lower federal capital gains rates. You owe the tax on your share of the income whether or not the entity paid you any cash that year.

For a California or Washington household earning $750,000 to $3 million, that last point is the one that causes trouble. A venture fund, private equity fund or real estate deal can allocate you $40,000 of gains in a year it distributes nothing, and there is no withholding on it. This guide explains how each type of K-1 income is taxed, how distributions differ from income, what the passive loss rules mean at your income, and how the same K-1 lands in California versus Washington.

Where a W-2 family’s K-1s usually come from

Most of the families we work with do not own a business. Their K-1s arrive because of investments and family structures:

• Private funds. Limited partner interests in venture capital, private equity, private credit or hedge funds, often bought through a bank platform or an employer’s alumni network. These report on Schedule K-1 (Form 1065).
• Real estate syndications. An apartment or industrial deal organized as an LLC taxed as a partnership. Also Form 1065.
• Publicly traded partnerships. Some energy and infrastructure holdings in a regular brokerage account issue a K-1 instead of a 1099.
• Trusts and estates. A beneficiary of a non-grantor trust or an estate receives Schedule K-1 (Form 1041) for income the trust passes out.
• S corporations. Less common for this reader, but a spouse’s equity in a small practice or startup can produce a K-1 (Form 1120-S).

The tax logic is similar across all three forms: the entity reports, and the owner or beneficiary pays. The rest of this article focuses on the partnership K-1, because that is the one most W-2 families see.

How each type of K-1 income is taxed federally for 2026

The partnership computes its income and splits it among the partners by the partnership agreement. Your K-1 then reports your share, box by box, and each box keeps the tax character it had inside the partnership. The IRS Partner’s Instructions for Schedule K-1 (Form 1065) tell you where each item goes on your return.

For 2026, the 37% bracket for married couples filing jointly starts at $768,700 of taxable income, and the 20% long-term capital gains rate applies above $613,700 (IRS Rev. Proc. 2025-32). The 3.8% Net Investment Income Tax applies to investment income once modified AGI passes $250,000 for a joint return, so nearly every family in this income range pays it on K-1 investment income.

One more line matters. If you are a limited partner, your share of the fund’s income is generally not subject to self-employment tax. Fixed payments a partnership makes to a partner for services are treated differently, but a passive investor in a fund rarely receives them. For more on that distinction, see whether K-1 income counts as earned income.

Are K-1 distributions taxable?

Usually not. You are taxed on your allocated share of income, not on the cash you receive. A distribution in box 19 generally just reduces your basis in the partnership. It becomes taxable only when a cash distribution exceeds your basis, and the excess is then treated as gain from selling your interest (see the Partner’s Instructions linked above).

This works in both directions. A fund can allocate income and distribute nothing, which is phantom income: you pay tax with no cash from the deal. Later, a real estate deal can distribute cash every quarter while the K-1 shows a loss from depreciation, so the cash arrives tax-deferred. The depreciation lowers your basis, so it shows up again as gain when the property is sold.

Your basis starts with what you contributed, goes up with allocated income and down with losses and distributions. Your K-1 shows a capital account, which is not the same number, so you or your CPA have to track basis yourselves. Keeping that running number, year by year, is one of the most useful records a family with private investments can keep.

The passive loss rules at a $750k+ income

A K-1 loss does not automatically reduce your tax. For a limited partner, losses are generally passive, and passive losses can only offset passive income (IRS Publication 925). They cannot offset your W-2 wages, RSU income or the interest and capital gains from your portfolio.

Many investors hear that rental losses of up to $25,000 can offset other income. That special allowance is for people who actively participate in their own rentals, limited partners generally are not treated as actively participating, and the allowance phases out completely once modified AGI reaches $150,000 (Publication 925). At this income level, assume it is zero.

Unused passive losses are not lost. They carry forward on Form 8582 and can offset future passive income, and they become fully usable when you dispose of your entire interest in the activity in a fully taxable sale to an unrelated buyer. This is why the “tax losses” in a syndication pitch deck are worth far less to a W-2 family than the deck suggests, unless the family also has passive income from other deals.

Worked example: the same K-1s in California and Washington

Assumptions, for illustration only. A married couple, both employees (a biotech scientist and an employed physician), earn $1.2 million in combined W-2 pay and have two children, ages 4 and 8. Their federal taxable income is about $1.1 million before any K-1 income, so they are well inside the 37% bracket and the 20% capital gains bracket for 2026. They hold two private investments:

1. A venture fund interest. For 2026 the K-1 shows $40,000 of net long-term capital gain (box 9a) and $2,000 of interest (box 5). The fund reinvested the proceeds and distributed nothing.
2. A real estate syndication. The K-1 shows a $15,000 net rental loss (box 2), mostly depreciation, and $6,000 of cash distributions (box 19).

Federal tax. The $40,000 gain is taxed at 20% plus 3.8% NIIT, or 23.8%: $9,520. The $2,000 of interest is taxed at 37% plus 3.8%, or 40.8%: $816. Federal total: $10,336.

The real estate loss. It is passive. The fund’s gain and interest are portfolio income, not passive income, so the loss cannot offset them, and it cannot offset wages. The $15,000 is suspended and carried forward. The $6,000 distribution is not taxed as long as their basis covers it; it reduces basis instead.

If they live in California. California taxes capital gains as ordinary income (FTB). Using the 2025 schedule (the latest the FTB has published), their taxable income sits in the 11.3% bracket for joint filers ($891,542 to $1,485,906), plus the 1% Behavioral Health Services Tax on taxable income above $1 million, for 12.3% on each extra dollar (FTB 2025 rate schedules). California tax on the $42,000: $5,166. Total tax on the K-1s: $15,502, against $6,000 of cash received.

If they live in Washington. Washington does not tax the interest in 2026. Its capital gains tax is 7% on long-term gains above a standard deduction that was $278,000 for 2025 (WA DOR), rising to 9.9% on taxable gains above $1 million. With no other large gains, their $40,000 falls under the deduction. Total tax on the K-1s: $10,336. Note that Washington has enacted a 9.9% income tax for individuals and joint filers with AGI over $1 million, starting January 1, 2028 (WA DOR), so this gap is expected to narrow for households at this income.

The practical lesson: the California family needs about $9,500 from somewhere else to pay the tax on these two K-1s, and none of it was withheld from a paycheck.

Timing: late K-1s and underpayment

A calendar-year partnership must give partners their K-1s by its return due date, March 15, and later if it files an extension (Form 1065 instructions). Private funds extend often, so K-1s arriving in the summer are normal. Families with several K-1s usually extend their own Form 1040 and pay an estimate by April 15, because an extension to file is not an extension to pay.

Because nothing is withheld on K-1 income, a W-2 household can underpay during the year even with large paycheck withholding. Federally, you generally avoid the underpayment penalty if withholding and on-time estimated payments cover 110% of the prior year’s tax when prior-year AGI was over $150,000 (IRS Publication 505). Raising W-4 withholding late in the year is one way to close a gap, since withholding is treated as paid evenly through the year.

Also check where the partnership operates. A fund or property in another state may require a nonresident return there, and California residents generally claim a credit for tax paid to the other state rather than paying twice. Your K-1 package usually includes a state schedule that shows this.

The decision the family actually has to make

The tax on a K-1 is rarely the reason to say yes or no to a private investment. The questions that matter for this reader are simpler:

• Do we have cash set aside for tax on income we may not receive in cash?
• Are we prepared to extend our return most years, and is our CPA set up for that?
• Are the promised “tax losses” usable for us, or will they sit suspended for years?
• In California, does the after-tax return still beat a simple taxable index fund, given that gains are taxed as ordinary income at the state level?

Where the answers are unclear, it can be worth reviewing private investments alongside your concentration in employer stock. See our investment risk management page, and for how K-1s compare with a brokerage account’s forms, K-1 vs 1099 tax treatment.

Common mistakes with K-1 income

• Filing before the last K-1 arrives. An amended return costs more than an extension. Keep a list of every entity expected to send one.
• Treating distributions as income. Box 19 is not what you are taxed on. The income boxes are.
• Losing track of basis. Without it, you cannot tell whether a large distribution is taxable or what your gain is when the fund winds down.
• Forgetting suspended losses. Form 8582 carryforwards need to follow you from CPA to CPA, or they are effectively gone.
• Reporting the entries in the wrong place. Each box routes to a different schedule. Our guide on where K-1 income goes on Form 1040 walks through it.

What to document for your kids

Private investments outlive the person who chose them. If one parent dies or becomes unable to manage money, the surviving spouse, the trustee and eventually the children need to know which entities send K-1s, where the capital account statements are, what the basis and suspended losses are, and why the family invested in the first place. A one-page record per investment, updated each spring when the K-1 arrives, covers most of it. Conversations fade. Documentation compounds.

Frequently asked questions

Is K-1 income taxed twice?

Not for a partnership or S corporation. These entities generally pay no federal income tax themselves; the income passes through and is taxed once, on the owners’ returns. Some states charge entity-level fees or taxes, and a trust pays tax on income it keeps rather than distributes, but the same dollar of partnership income is not taxed federally at both the partnership and the partner level.

Do I have to pay tax on K-1 income if I received no money?

Yes. You are taxed on your share of the partnership’s income for the year as allocated to you, whether or not it distributed cash. This is common with venture and private equity funds that reinvest proceeds. Families holding several funds often keep a separate cash reserve for this tax, since nothing is withheld on K-1 income.

Can I file my taxes without my K-1?

You should not file a return that leaves out K-1 income you know is coming. If a K-1 is late, the usual step is to file Form 4868 for an automatic extension and pay your best estimate of the tax by April 15. Estimating from the prior year’s K-1 or the fund’s own estimate letter is common practice.

Next step

Before the next tax season, make a list of every entity that sends your family a K-1, with the expected arrival month and your current basis in each. If you would like a second set of eyes on how private investments fit with your RSUs and tax picture, our tax management team starts with a Tax & Wealth Assessment.

This is general education, not individual tax advice. The right treatment depends on your family’s full picture and your partnership agreements.

Written by

Kevin Luu

Co-Founder and Chief Learning Officer, Bright Advisers

Kevin has advised high-income W-2 tech and biotech families since 2015, and leads the education-first Age Five Family Office from Brea, California.

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