Intermediate4 min read

K-1s and Partnership Structures

Some listed securities are partnerships rather than corporations. They report on a K-1 instead of a 1099, arrive late, and carry consequences that surprise holders.

MadStockAlerts Research · Updated August 29, 2026

What to take away

  • A partnership passes income through to holders, who report their share.
  • The reporting form is a K-1, which frequently arrives after the filing deadline.
  • Distributions are generally not dividends and reduce cost basis.
  • They can generate income taxable in states where the holder does not live.
  • Holding them inside a retirement account can generate its own tax problem.

MAD Academy Training Video · 0:45

The Form That Arrives After the Deadline

Partnership structures pass income through to holders on a K-1, which changes both the paperwork and the timing of your filing.

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What a pass-through structure does

A corporation pays tax on its profits and then distributes what remains as dividends. A partnership does not pay tax at the entity level: it allocates its income, deductions and credits to its partners, who report their share on their own returns.

Buying units in a publicly traded partnership therefore makes the holder a partner in a business rather than a shareholder in a corporation, and the reporting follows from that legal fact rather than from anything about the security's price behaviour.

This describes how the rules are structured and is not tax advice. Tax rules change, they interact, and the treatment of any particular situation depends on circumstances that only a qualified professional can assess.

The K-1, and when it arrives

1099K-1
Issued byThe brokerThe partnership
Typical arrivalEarly in the yearFrequently late, sometimes after the filing deadline
ContentsDividends, interest, proceedsAllocated income by category, deductions, credits, state detail
ComplexityStandardMultiple pages, often with state-by-state schedules

The second row is the practical problem. A single unit of a partnership held in an otherwise simple account can delay a return, and the form's arrival is outside both the holder's and the broker's control.

Distributions and basis

Cash paid by a partnership is generally a distribution rather than a dividend. It is often not taxed on receipt and instead reduces the holder's basis in the units, which increases the eventual gain on sale.

Over a long holding period this can reduce basis substantially, and a sale then produces a larger gain than the price appreciation alone suggests. Part of that gain may also be recharacterised as ordinary income under recapture rules.

This is the mechanism behind a recurring surprise: a position sold near its purchase price producing a significant taxable gain. Nothing went wrong; the basis had been reduced by years of distributions.

Distributions reduce basis, so the eventual gain grows
Distributions reduce basis, so the eventual gain grows1020304050Sold at roughly the purchase price,with a $26 gainYear 0246810$ per unit

Scroll the chart sideways to see all of it.

  • Price
  • Cost basis
A position sold near its purchase price can still produce a substantial taxable gain, because years of distributions reduced the basis. Illustrative.

Two further consequences

  • State filing: income allocated to states where the partnership operates can create filing obligations in states the holder has never been to, subject to thresholds.
  • Retirement accounts: partnerships can generate unrelated business taxable income, which can be taxable inside an account that is otherwise tax-exempt, with its own filing requirement.

The second is the one most often described as a trap, and it is a documented feature of the structure rather than a quirk. Both are exactly the kind of interaction that depends on amounts and thresholds a professional would check. This describes how the rules are structured and is not tax advice. Tax rules change, they interact, and the treatment of any particular situation depends on circumstances that only a qualified professional can assess.

Where these structures appear

Publicly traded partnerships are concentrated in a small number of sectors, which is a consequence of the qualifying income rules that permit the structure.

SectorWhy the structure is used
Energy infrastructurePipeline and storage income qualifies, and the structure avoids entity-level tax
Natural resourcesExtraction and processing income qualifies
Some commodity fundsStructured as partnerships and reporting on a K-1
Some volatility and futures productsHold futures and are taxed under their own regime

The last two rows are the ones that catch people unaware. A product bought on an exchange like any other fund can turn out to be a partnership, with a K-1 arriving in place of a 1099 and a different tax treatment behind it.

The structure is disclosed in the product's own documents, which is where it can be established before rather than after. This describes how the rules are structured and is not tax advice. Tax rules change, they interact, and the treatment of any particular situation depends on circumstances that only a qualified professional can assess.

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