K-1 Tax Rate: How K-1 Income Is Taxed for High-Earning Families

There is no single K-1 tax rate. A Schedule K-1 splits your share of a partnership’s, S corporation’s or trust’s income into types, and each type is taxed at the rate that applies to it on your own return: ordinary business income and interest at your regular bracket (up to 37% for 2026), qualified dividends and long-term capital gains at 0%, 15% or 20%, and some real estate gains at up to 25%. Once joint modified AGI passes $250,000, which covers virtually every household earning $600,000 or more, add the 3.8% Net Investment Income Tax on most passive K-1 income, plus state tax, which in California means up to 13.3% on every type, gains included (2025 schedule, the latest published).

You also owe tax on your allocated share whether or not the fund sends you any cash. The IRS instructions put it plainly: a partner may be liable for tax on their share of partnership income “whether or not distributed” (Partner’s Instructions for Schedule K-1, Form 1065).

Where high-earning W-2 families pick up K-1s

Most of the families we work with never set out to own a business. The K-1s arrive anyway, usually from one of these:

• A real estate fund or syndication a colleague recommended.
• A venture or private equity fund, often through an employer’s feeder program or an angel group.
• A publicly traded partnership (energy pipelines, some commodity funds) bought in a brokerage account.
• A spouse’s medical practice or professional partnership, where the K-1 replaces or sits alongside a W-2.
• A family trust or estate that passes income out to beneficiaries (a Form 1041 K-1).

For a household already paying the top rate on salary and RSU vests, a K-1 is rarely a large amount of tax on its own. The friction is elsewhere: it arrives late, it can create tax without cash, and its losses often cannot be used against wages.

How each K-1 box is taxed for 2026

The table below uses a married couple filing jointly with taxable income above $768,700, where the 37% federal bracket starts for 2026, and modified AGI above the $250,000 threshold for the Net Investment Income Tax. That typically means gross household income well above $850,000 once 401(k) deferrals and deductions come off. If your joint taxable income is between $512,450 and $768,700 (the 35% bracket for 2026), read 35% instead of 37% in the ordinary-income rows.

Sources for the rates: brackets and capital gains breakpoints from IRS Rev. Proc. 2025-32 (for 2026 the 20% rate applies above $613,700 of taxable income for joint filers), the 25% maximum from IRS Topic 409, qualified dividend treatment from IRS Topic 404, and the 3.8% tax from the IRS Net Investment Income Tax page and Form 8960 instructions, which include income from a trade or business that is passive to you.

Box 1 income may also qualify for the qualified business income deduction of up to 20% (IRS QBI page). At incomes like these, the deduction is subject to a taxable income limitation, and it depends on the fund reporting the needed details in box 20. Treat it as a possible reduction, not something to count on when you estimate.

Worked example: a $900,000 California household with two fund K-1s

Assumptions (illustrative): married filing jointly, two children, one spouse at a Bay Area biotech with RSUs and one a hospital-employed physician. Combined W-2 income is about $900,000 and both federal and California taxable income are about $800,000 before the K-1s. They hold one real estate fund and one venture fund, both passive. We use 2026 federal rates and California’s 2025 schedule (10.3% for joint taxable income from $742,958 to $891,542), since California had not published 2026 brackets when this was written. We ignore any QBI deduction.

Their K-1s show $20,000 of ordinary business income, $5,000 of interest, $10,000 of qualified dividends and $30,000 of long-term capital gains: $65,000 in total. The funds distributed $40,000 of cash.

Three things stand out. First, the tax follows the $65,000 of allocated income, not the $40,000 of cash. Second, the blended federal rate is not “the K-1 rate” of any one number: it runs from 23.8% to 40.8% depending on the box. Third, California taxes the gains and dividends at the same 10.3% as the interest, because California has no lower rate for capital gains.

The Washington column assumes the same family lived in Seattle. Washington has no wage income tax for 2026, and its 7% capital gains tax only applies to long-term gains above the annual standard deduction ($278,000 for 2025, the latest the Department of Revenue has published). The DOR confirms individuals can owe it on gains from their interest in a pass-through entity, while gains directly attributable to real estate the entity owns directly are exempt. $30,000 of fund gains alone stays under the deduction, but long-term gains on vested RSU shares held more than a year count toward the same threshold, so a year with a large stock sale can pull K-1 gains into the tax. Gains above $1 million of taxable gains are taxed at 9.9%. Washington has also enacted a 9.9% income tax on AGI over $1,000,000 starting January 1, 2028 (DOR income tax page), so the Washington column will change for the highest earners.

Distributions are not the taxable number

Box 19 shows cash or property the partnership paid you. Those distributions are generally not taxed when you receive them. They reduce your basis in the investment instead. Generally, only a cash distribution larger than your adjusted basis creates a taxable gain, per the K-1 instructions. This is why a fund can send you $40,000 while your K-1 reports $65,000 of income, or send $40,000 while reporting a loss.

The practical effect: generally nothing is withheld on K-1 income. If a fund allocates meaningful income, the tax has to come from estimated payments or extra withholding on your W-2 or RSU vests. Many high earners already under-withhold on RSUs, since the optional 22% federal supplemental rate for 2026 is well below a 35% or 37% bracket (IRS Publication 15). A K-1 adds to that gap.

Why K-1 losses usually cannot offset your salary

Real estate funds often report losses in the early years, mostly depreciation. For a passive investor, those losses go through Form 8582 and can generally only offset passive income, not wages or RSU income (IRS Publication 925). The special allowance that lets some rental owners deduct losses against salary phases out at incomes well below this household’s. Unused losses carry forward and are generally released when you dispose of your entire interest in the activity.

So a $30,000 K-1 loss generally does not cut a $900,000 household’s tax this year, unless the family has passive income from other investments for it to absorb. It is a deferred benefit, worth tracking carefully, because it can offset the gain when the fund sells its buildings.

If one of you is a partner in a practice

A physician or attorney who is a partner, not an employee, gets a K-1 with self-employment earnings in box 14. That income is taxed at ordinary rates and is subject to self-employment tax rather than the 3.8% Net Investment Income Tax. Social Security tax stops at the 2026 wage base of $184,500 for wages and self-employment earnings combined; the 2.9% Medicare portion has no cap, and the 0.9% Additional Medicare Tax applies above $250,000 for joint filers (Pub 15, IRS Additional Medicare Tax page). If the other spouse’s W-2 already exceeds the wage base, that does not change the partner-spouse’s Social Security calculation: the wage base applies per person. The $250,000 Additional Medicare Tax threshold, by contrast, counts both spouses’ wages and self-employment income together.

When K-1s arrive, and why many families extend

A partnership must send K-1s by the due date of its own return, which is March 15 for a calendar-year partnership, or later if the partnership files an extension (Form 1065 instructions). Private funds extend routinely. Families with fund K-1s often extend their own 1040 with Form 4868, which extends the filing deadline but not the payment deadline. A common pattern is to estimate the K-1 tax in early April from last year’s K-1 and the fund’s year-end letter, pay any remaining balance with the extension, and file once every K-1 is in. An extension does not waive the penalty for underpaying during the year, which is why expected K-1 income usually belongs in quarterly estimated payments or extra withholding (IRS Form 2210). Filing early and then receiving a corrected K-1 can mean an amended return.

Common mistakes we see

• Taxing the distribution instead of the allocation. The cash in box 19 is not the income. Boxes 1 through 11 are.
• Assuming a K-1 loss reduces this year’s tax. For passive investors at this income, it usually does not.
• Using one “K-1 rate” in projections. Ordinary income at 51.1% and gains at 34.1% in the California example are very different planning numbers.
• Forgetting withholding. K-1 income adds to the balance many RSU households already owe in April.
• Losing basis records. Without a running record of contributions, allocations and distributions, the gain on sale can be misstated years later.

What to write down for your kids and executor

Private fund interests outlive the person who made the decision. If something happened to you, could your spouse or executor say which funds you own, why you chose them, when the K-1s usually arrive, who your CPA is, and where the basis records live? A one-page note per investment, updated each spring when the K-1 comes in, answers most of that. It also gives your children something real to learn from later: why you invested, what you expected, and what actually happened. Conversations fade. Documentation compounds. This is the kind of note the FamilyKnowledge® Library is built to hold.

If a family trust or partnership ever passes K-1 income to your children, the kiddie tax applies: for 2026, a child’s unearned income over $2,700 is generally taxed at the parents’ rate (Rev. Proc. 2025-32, Form 8615 instructions). Shifting fund income to children under 18 rarely lowers the family’s rate.

Frequently asked questions

Are K-1 distributions taxed?

Generally no, not when you receive them. You are taxed on your allocated share of income shown in the income boxes, whether or not it is paid out. Distributions reduce your basis in the investment. A distribution becomes taxable only when it exceeds your basis, and then it is usually treated as gain. Keep each year’s K-1 so your basis can be tracked accurately.

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

Only some of it. A general partner or active partner in a practice typically has self-employment earnings in box 14. A limited partner in a real estate or venture fund usually does not, but that passive income is typically subject to the 3.8% Net Investment Income Tax once modified AGI is above $250,000 for joint filers. More on this in whether K-1 income counts as earned income.

Is K-1 income taxed more than 1099 income?

Not by itself. The rate depends on the type of income, not the form it is reported on. Interest is taxed the same way on a 1099-INT or a K-1. The differences are timing, losses that may be limited as passive, and possible self-employment tax. See K-1 vs 1099 tax rate for a side-by-side comparison.

Next step

Before the next K-1 season, list every entity that sends you a K-1, last year’s amounts by box, and whether the fund extends. That list is enough to estimate April’s payment and decide whether to extend. For how each box flows onto your return, see where K-1 income goes on Form 1040, and for timing, when to expect your K-1. If you want a second look at how K-1s, RSUs and withholding fit together, our tax management and investment risk management teams review this as part of the Tax & Wealth Assessment.

This article is general education, not individual tax advice. The right move depends on your family’s full picture.

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

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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