S corp vs. partnership: the self-employment tax differences that actually matter
Both are "pass-through" entities that skip corporate income tax — so the headline comparisons you'll read online are mostly noise. The real fight is over whose paycheck the IRS gets to tax at 15.3%, and four days before we published this, the Second Circuit just made that fight a lot more serious for anyone calling themselves a "limited partner" who isn't one.
Here's the confusion that costs small-business owners real money: people compare "S corp" and "partnership" as if they were two competing types of company. They aren't. An S corporation is a federal tax election (made on Form 2553) layered on top of a state-law corporation or LLC. A partnership, for this purpose, usually means a general partnership, an LLP, or — most commonly today — a multi-member LLC that hasn't elected corporate tax treatment. Both are pass-through entities: neither pays federal income tax at the entity level, and profit flows through to the owners' personal returns either way.
So the income-tax rate isn't the story. The story is self-employment tax, who can own the business, and how losses and distributions work — three areas where these structures genuinely diverge, sometimes by tens of thousands of dollars a year.
Four ways they actually differ
Click through the tabs below — each covers one dimension where the choice of structure has real tax consequences.
Partnership / multi-member LLC
Under IRC §1402(a), a partner's entire distributive share of trade-or-business income counts as net earnings from self-employment — whether or not it's ever distributed in cash. Any guaranteed payment for services under §707(c) is added on top. The only carve-out is §1402(a)(13), which excludes "the distributive share of any item of income or loss of a limited partner, as such" — a narrow exception built for passive investors, not working owners (more on this below).
S corporation
Since Rev. Rul. 59-221 (1959), an S-corp shareholder's undistributed share of corporate income has never been subject to self-employment tax. Instead, a shareholder who works in the business must be paid reasonable compensation as a W-2 employee, and only that salary is subject to FICA (Social Security and Medicare). Everything paid out above it comes through as a distribution under §1368, taxed as ordinary pass-through income but carrying no payroll tax at all.
Partnership / multi-member LLC
Ownership is essentially unrestricted. Partners can be individuals, corporations, other partnerships, trusts, tax-exempt organizations, or nonresident aliens — and there's no cap on the number of partners. A multi-member LLC defaults to partnership tax treatment automatically under the "check-the-box" regulations (Treas. Reg. §301.7701-3) unless it elects otherwise.
S corporation
IRC §1361(b) imposes real limits: no more than 100 shareholders (family members can elect to be counted as one, under §1361(c)(1)); shareholders must be individuals, estates, or certain trusts (grantor trusts, QSSTs, ESBTs) — not partnerships or corporations, and not nonresident aliens (§1361(b)(1)(C)); and only one class of stock is allowed (differences in voting rights are fine under §1361(c)(4); differences in distribution or liquidation rights are not). One ineligible shareholder, or an inadvertent second class of stock, can terminate the entire election.
Partnership / multi-member LLC
A partner's outside basis (§705) includes their share of the partnership's liabilities under §752 — so debt the entity borrows can itself generate basis that lets losses flow through. Allocations of profit, loss and cash can be disproportionate to ownership percentage, as long as they have "substantial economic effect" under §704(b) — useful for deals where partners contribute differently (cash vs. sweat equity, for example).
S corporation
A shareholder's basis (§1367) is built from their stock plus any amounts they personally lent to the corporation — not the corporation's own third-party debt, even if the shareholder guaranteed it. Losses are limited to basis under §1366(d), with the excess suspended and carried forward. Because there's only one class of stock, distributions must be strictly pro-rata to shares held — there's no equivalent to a partnership's flexible special allocations.
Partnership / multi-member LLC
Under Rev. Rul. 69-184, a partner can never be a W-2 employee of their own partnership — even if they do work that looks exactly like an employee's. They're paid through guaranteed payments or their distributive share instead, with no payroll withholding, and they deduct self-employed health insurance on their own return under §162(l) rather than receiving it as a tax-free employer benefit. Treasury finalized regulations in 2019 confirming this rule even applies when a partnership tries to route partners through a disregarded-entity "employer."
S corporation
Shareholder-employees genuinely are W-2 employees — but IRC §1372 treats any 2%-or-more shareholder as a partner for fringe-benefit purposes. In practice, that means health insurance the company pays for a 2%+ shareholder must be added to Box 1 of their W-2 (per IRS Notice 2008-1), though it's exempt from FICA/FUTA if the requirements are met, and the shareholder then claims the self-employed health insurance deduction personally. The company must also run real payroll — W-2s, quarterly Form 941, state unemployment insurance — for every shareholder-employee.
Run your own numbers
The payroll-tax gap between the two structures depends entirely on your profit level and the salary you'd actually pay yourself under an S-corp election. Enter your figures and compare both scenarios side by side.
Partnership / LLC
S corporation
Side by side: the full comparison
| Partnership / multi-member LLC | S corporation | |
|---|---|---|
| Entity-level income tax | None (pass-through) | None (pass-through) |
| SE tax / FICA on profit | Entire distributive share, generally | Reasonable salary only |
| Ownership limits | None — any number/type of owner | Max 100 shareholders, no nonresident aliens, no entity owners |
| Classes of ownership interest | Flexible; special allocations allowed | One class of stock only |
| Basis includes entity-level debt? | Yes, per §752 | No — only direct shareholder loans |
| Owner can be a W-2 employee? | No (Rev. Rul. 69-184) | Yes — and generally must be, if working |
| Owner's pay counts as W-2 wages for §199A wage limit? | No — guaranteed payments don't count | Yes — reasonable salary counts |
| Election fragility | None | One bad shareholder or share class can blow the election |
| Compliance overhead | Partnership return (Form 1065) + K-1s | Payroll + corporate return (Form 1120-S) + K-1s |
The 15-year fight over who counts as a "real" limited partner
The §1402(a)(13) exception was written for people who simply invest and take no active role. In Renkemeyer, Campbell & Weaver, LLP v. Commissioner, 136 T.C. 137 (2011), the Tax Court held that lawyers running their own law firm as an LLP were not limited partners "as such," because their income came from services, not investment — creating the functional analysis test that still governs today. Castigliola v. Commissioner, T.C. Memo. 2017-62, extended the same logic to LLC members: three lawyer-owners who managed their own firm couldn't treat any of their income as a passive limited partner's share, because "they ran the business, and they had only one type of ownership interest."
The fight then moved to real, state-law limited partnerships — where the IRS had to show that a formal "limited partner" label didn't reflect reality. In Soroban Capital Partners LP v. Commissioner, the Tax Court ruled the fund's "limited partners" (who ran the firm full-time, sat on governing committees and made hiring decisions) were limited partners in name only. On September 17, 2026, the Second Circuit affirmed, holding that the 1977 meaning of "limited partner" requires both limited liability and abstention from managing the business — though it clarified that providing some services doesn't automatically disqualify someone. A companion case, Denham Capital Management LP v. Commissioner, T.C. Memo. 2024-114, applied the same functional test and currently sits on appeal at the First Circuit.
Meanwhile, the Fifth Circuit has taken a related but distinct path. Its original opinion in what was captioned Sirius Solutions, LLLP v. Commissioner (decided January 2026) suggested a taxpayer-friendlier, near-bright-line rule: state-law limited-partner status plus limited liability could settle the question on its own. The court then withdrew that opinion and substituted a new one on August 12, 2026, under the caption K Alain, LLLP v. Commissioner, adopting a "significant role in managing or running the business" standard instead — explicitly rejecting the Tax Court's stricter approach as "divorced from statutory text." The Second Circuit has since noted "little daylight" between its own test and the Fifth Circuit's, but the two courts did not arrive there the same way, and the First Circuit's pending Denham appeal could still open a genuine split.
What this means if you're not a hedge fund: none of this nuance helps a typical small-business LLC member who actively works in and helps run the company. Every one of these cases — from Renkemeyer through the 2026 circuit decisions — agrees on one point: if you manage the business, you are not a limited partner "as such," regardless of your title or your operating agreement. A related, unfinalized 1997 proposed regulation lists three factors courts still reference: personal liability for partnership debts, authority to contract on the partnership's behalf, and participation exceeding 500 hours a year. Meeting any one of these has historically weighed against limited-partner treatment.
Reasonable compensation: what the Watson case means for your salary number
There's no statutory formula for "reasonable compensation" — it's a facts-and-circumstances test, and the IRS has been willing to litigate low salaries for decades. In David E. Watson, P.C. v. United States, 668 F.3d 1008 (8th Cir. 2012), a CPA and sole shareholder paid himself just $24,000 in salary while his S-corp generated over $2 million in revenue and paid him roughly $200,000 a year in distributions. The Eighth Circuit upheld the IRS's recharacterization of a large chunk of those distributions as wages, accepting an expert's calculation that $91,044 was the reasonable salary for his role — and rejecting the argument that the company's own stated intent should control.
The IRS's own published factors for evaluating reasonable compensation include: training and experience; duties and responsibilities; time and effort devoted to the business; dividend history; pay to non-shareholder employees; the timing and manner of paying bonuses to key people; what comparable businesses pay for similar services; compensation agreements; and whether a consistent formula is used. The IRS is explicit that compensation must be paid before any non-wage distribution, and that routing what is really pay for services through distributions instead of wages doesn't avoid employment tax — it just moves the fight to audit.
There's no bright-line percentage in the law itself linking salary to profit. As a practical matter, though, a salary far below what an unrelated employee would be paid for the same work — especially alongside large, regular distributions — is the fact pattern that has consistently lost in court.