By Harry Prabandham · Updated September 28, 2026
Investing & Markets
Master Limited Partnerships (MLPs): Structure, K-1 Taxes, and Risks
An MLP is a publicly traded partnership, usually in energy infrastructure. It avoids corporate tax but sends investors a K-1 and complex basis rules.
Master Limited Partnerships (MLPs): Structure, K-1 Taxes, and Risks
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What is a master limited partnership?
- An MLP is a partnership whose units trade on a stock exchange, combining partnership taxation with exchange liquidity.
- Publicly traded partnerships are taxed as corporations unless at least 90% of their gross income is qualifying income, such as from natural resource activities.
- That rule is why most MLPs operate pipelines, storage, processing, and other energy infrastructure.
- Investors own units and are limited partners, while a general partner manages the business.
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What is a master limited partnership?
- An MLP is a partnership whose units trade on a stock exchange, combining partnership taxation with exchange liquidity.
- Publicly traded partnerships are taxed as corporations unless at least 90% of their gross income is qualifying income, such as from natural resource activities.
- That rule is why most MLPs operate pipelines, storage, processing, and other energy infrastructure.
- Investors own units and are limited partners, while a general partner manages the business.
How are MLP distributions taxed?
- The partnership pays no federal income tax; each unitholder reports a share of income, deductions, and credits from a Schedule K-1.
- Distributions are often largely a return of capital, which is not taxed when received but reduces your cost basis.
- When units are sold, part of the gain tied to prior depreciation is generally taxed as ordinary income rather than capital gain.
- Qualified publicly traded partnership income can be eligible for the 20% Section 199A deduction, which the 2025 tax law made permanent.
Why can K-1s complicate a tax return?
- K-1s often arrive later than 1099 forms, which can delay filing or require an extension.
- Owning an MLP can create filing obligations in states where the partnership operates.
- Basis must be tracked each year, and basis can fall to zero after years of distributions.
- Because of this complexity, many MLP owners work with a CPA; Rubric Advisors does not prepare tax returns.
Can MLPs be held in an IRA?
- MLP income held in an IRA can be unrelated business taxable income.
- If an IRA's gross UBTI reaches $1,000 in a year, the IRA generally must file Form 990-T and may owe tax, paid from the IRA.
- That can reduce or offset the tax deferral that usually makes an IRA attractive.
- Funds that hold MLPs file their own returns, so fund investors generally receive a 1099 rather than a K-1.
How do MLP funds differ from owning units directly?
- A regulated mutual fund or ETF can hold no more than 25% of its assets in qualified publicly traded partnerships.
- Funds that exceed that level are organized as C corporations, which pay corporate income tax that reduces what shareholders receive.
- Exchange-traded notes linked to MLP indexes avoid K-1s but add the issuer's credit risk.
- Each structure trades tax simplicity against cost, tracking accuracy, or credit exposure.
What are the main risks of MLPs?
- Distributions are not fixed and can be cut if cash flow falls, as has happened in past energy downturns.
- Volumes, commodity prices, counterparty credit, and energy-transition policy can all affect results.
- Many MLPs carry substantial debt, which increases sensitivity to interest rates and credit markets.
- Regulatory, environmental, and governance risks, including general partner conflicts, add further uncertainty.
Key takeaways
- MLPs are publicly traded partnerships, mostly in energy infrastructure, that avoid entity-level federal tax.
- Return-of-capital distributions defer tax but lower basis, and part of the gain on sale is taxed as ordinary income.
- K-1s, state filings, and UBTI in IRAs add complexity that funds can simplify at a cost.
- Confirm the tax treatment for your situation with a CPA.
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