Master Limited Partnerships (MLPs)

How it works

A master limited partnership is a limited partnership whose units trade on a public exchange. It pays no entity-level federal income tax; income, deductions and credits pass through to unitholders in proportion to units held, which is the same pass-through logic as a private partnership, just with a stock-ticker wrapper.

Access to that no-entity-tax status depends on the Section 7704 qualifying-income test: at least 90% of gross income must come from qualifying sources, principally the exploration, production, transportation, processing, storage and marketing of minerals and natural resources, plus real property rents and certain interest and dividends. That test is why the MLP universe is dominated by midstream energy infrastructure — pipelines, gathering systems, fractionators, terminals and storage — rather than being a general-purpose business structure open to any industry.

The general partner runs day-to-day operations; a unitholder is a limited partner with no management role and, at most partnerships, very limited voting rights. Revenue is typically fee-based — shippers pay a tariff per barrel or per thousand cubic feet moved, often under take-or-pay contracts that charge for reserved capacity whether or not it is used, sometimes with inflation-linked escalators built in.

Many older MLPs carried incentive distribution rights that paid the general partner a rising share of cash flow as distributions grew; most large partnerships eliminated or bought out these rights during a 2017–2020 simplification wave because the escalating GP take made new projects uneconomic. Some sponsors went further and converted the MLP into a corporation outright, a reminder that the structure is a choice management can unwind, not a permanent feature of the security.

What it pays

The payout is quoted as a distribution yield on the unit price and is usually paid quarterly. The word distribution rather than dividend is not marketing language — it reflects a genuinely different tax treatment described below.

The internal metric that matters is distributable cash flow, a non-GAAP figure roughly equal to operating cash flow less maintenance capital spending, and the distribution coverage ratio, DCF divided by distributions paid. Yields tend to run structurally higher than similarly risky corporate equities, partly because the entity itself pays no tax and partly because K-1 paperwork narrows the pool of willing buyers, which supports a higher yield to compensate.

Distribution growth comes from three places: rising throughput volumes on existing assets, contracted tariff escalators, and new pipeline or terminal projects entering service. Fee-based midstream cash flow is less exposed to commodity prices than upstream production is, but it is not insulated — volumes fall when producers cut drilling, and counterparty risk rises when the producers behind a system are financially stressed.

Discipline around coverage changed materially after 2020. Many partnerships now target coverage ratios well above one times distributable cash flow and fund growth spending internally rather than issuing new units, which has slowed distribution growth rates but also reduced the odds of an abrupt cut.

Costs and taxes

A unitholder receives a Schedule K-1, not a Form 1099-DIV, listing a share of the partnership's income, deductions, depreciation and tax credits. K-1s frequently arrive later in the tax season than 1099s, which can force a filing extension.

Because depreciation and other deductions flow through, cash distributions are generally not taxed as income when received; instead most of the distribution is treated as a return of capital that reduces the unitholder's basis, deferring tax until sale. On sale that deferral reverses: the accumulated basis reduction increases the taxable gain, and the portion attributable to previously claimed depreciation is recaptured as ordinary income rather than taxed at capital-gains rates.

The partnership's operations can create tax filing obligations in every state where it does business, a real compliance burden for a sizeable position. Inside an IRA or other tax-exempt account, MLP income can generate unrelated business taxable income; if total UBTI across the account exceeds $1,000 in a year, the custodian must file Form 990-T and the account itself pays the tax, which erodes the account's tax-exempt advantage.

MLP-focused ETFs and closed-end funds sidestep the K-1 by issuing a standard 1099, but a fund holding more than 25% in MLPs cannot qualify as a regulated investment company and must instead be taxed as a C corporation, accruing deferred tax on unrealized gains — a drag that shows up as tracking error against the underlying MLP index.

Liquidity and time commitment

Units trade on the exchange with the same immediacy as ordinary stock; the friction in this asset class is tax paperwork, not the ability to exit a position during market hours.

The ongoing commitment is administrative rather than operational: assembling K-1s each spring, tracking cumulative basis adjustments year over year, and potentially filing state returns in jurisdictions where the partnership operates. Selling units requires a supplemental K-1 sales schedule to separate ordinary recapture from capital gain — standard brokerage cost-basis reporting does not capture this correctly on its own.

Gifting units, inheriting them, or holding them jointly across a marriage or in a trust all introduce basis complications that a plain stock position does not have. For an investor who wants the sector exposure without the K-1 workload, fund wrappers substitute an expense ratio, and in the C-corporation fund structures, a deferred tax drag, for the paperwork.

How it goes wrong

Distribution cuts are a recurring feature of the sector's history, not a tail event: the 2015–2016 energy downturn and the 2020 demand collapse both produced large distribution reductions, including at partnerships that had never cut before.

The basis trap is specific to this structure — an investor who holds for many years while distributions steadily reduce basis toward zero eventually starts recognizing taxable gain on further distributions received, and faces significant depreciation recapture taxed as ordinary income when the units are finally sold. Holding units in an IRA introduces a separate mismatch: UBTI can trigger a Form 990-T filing and tax paid inside a wrapper that was supposed to be tax-deferred or tax-free.

A sponsor's decision to convert the partnership into a corporation crystallises the deferred tax on the unitholder's own return, at a time and price the unitholder did not choose. Fee-based contracts reduce but do not eliminate commodity exposure: if the producers behind a gathering system stop drilling or file for bankruptcy, contracts can be renegotiated, rejected in bankruptcy court, or simply not renewed.

K-1 friction is a smaller but persistent cost: late or amended K-1s force extensions and amended returns, and for a modest position the accounting time can exceed the after-tax income produced. Underlying all of this is a governance limit — limited partners have limited voting rights, and the general partner controls major decisions including asset sales and any decision to change the structure itself.