Wade owns 40 percent of an oilfield-services LLC in Artesia. He schedules the crews every morning and signs the equipment leases himself. The LLC files a partnership return, and for years its preparer has put a zero on the self-employment line of Wade’s K-1, reasoning that a member with limited liability is close enough to a limited partner to skip Social Security and Medicare tax on his profit share.
That reasoning had a bad September. The Second Circuit ruled for the IRS on September 17, 2026, adopting the Tax Court’s view of the limited partner exclusion, five weeks after the Fifth Circuit rewrote its own test. Both cases involved investment firms, and neither court hears New Mexico appeals. The rule lands harder on operating LLCs here, where owners do the work.
Does a New Mexico LLC member owe self-employment tax on K-1 income?
Usually, yes. Self-employment tax is 12.4 percent for Social Security and 2.9 percent for Medicare (26 U.S.C. § 1401). Net earnings from self-employment include the slice of partnership business income allocated to each partner, “whether or not distributed” (26 U.S.C. § 1402(a)). Section 1402(a)(13) carves out “the distributive share of any item of income or loss of a limited partner, as such,” though guaranteed payments for services stay taxable.
An LLC member is not a limited partner under New Mexico law at all. The Limited Liability Company Act, NMSA 1978, § 53-19-1 et seq., shields members from company debts (NMSA 1978, § 53-19-13), while limited partners exist under a separate statute, NMSA 1978, ch. 54, art. 2A. The question becomes whether he functions like a limited partner, as such. Congress never defined the term.
What does “limited partner” mean in section 1402(a)(13) after Soroban and K Alain?
Congress wrote the exclusion in 1977 with passive investors in mind. Treasury’s January 1997 proposal, 62 Fed. Reg. 1702 (Prop. Treas. Reg. § 1.1402(a)-2(h)), would have denied limited partner treatment to anyone personally liable for partnership debts, holding authority to contract for the entity, or working more than 500 hours a year. Congress responded in § 935 of the Taxpayer Relief Act of 1997, barring final or temporary regulations before July 1, 1998. Nothing was finalized, and the 2026-2027 Priority Guidance Plan (September 29, 2026) lists no project on it.
In Renkemeyer, Campbell & Weaver, LLP v. Commissioner, 136 T.C. 137 (2011), law partners who paid $110 each for their interests owed the tax on shares earned by legal work. Soroban Capital Partners LP v. Commissioner, 161 T.C. 310 (2023), read “as such” to reach only a limited partner “who is functioning as a limited partner,” and T.C. Memo. 2025-52 applied that functional analysis test. The Second Circuit affirmed (Nos. 25-2079, 25-2250), defining the term as a partner who, “in addition to having limited liability, does not run, manage, or control the partnership’s business.”
On August 12, 2026, granting panel rehearing in No. 24-60240, the Fifth Circuit withdrew Sirius Solutions, L.L.L.P. v. Commissioner, 165 F.4th 374 (5th Cir. 2026), and substituted K Alain, L.L.L.P. v. Commissioner; Sirius had changed its name. A limited partner is now one “who plays no significant role in managing or running a business,” and the case went back for the facts over a dissent. The taxpayer reportedly sought en banc review in late September. Denham Capital Management LP v. Commissioner, T.C. Memo. 2024-114, argued in the First Circuit (No. 25-1349) in February 2026, was undecided when I checked.
Which rule applies to a New Mexico LLC, and what has the Tenth Circuit said?
Nothing yet. I found no Tenth Circuit or Tenth Circuit BAP opinion construing § 1402(a)(13). An individual’s Tax Court case is appealable to the circuit of his legal residence under 26 U.S.C. § 7482(b)(1)(A), which for Wade is the Tenth Circuit.
Under Golsen v. Commissioner, 54 T.C. 742 (1970), aff’d, 445 F.2d 985 (10th Cir. 1971), the Tax Court follows an appellate decision “squarely in point” only from the circuit that will hear the appeal. With no Tenth Circuit ruling, a New Mexico member in Tax Court (see the firm’s post on New Mexico Tax Court trial locations) should expect Soroban and Denham to govern. K Alain becomes an argument for the Tenth Circuit, not a rule the trial judge must apply.
How would the functional analysis test treat an Artesia oilfield-services LLC?
Denham asks where the partnership’s income comes from, what the partner does to generate it, and how his share relates to the capital he put in, and the taxpayer carries the burden. An oilfield-services company earns its money from crews and equipment, and Wade runs it full time. Unless his capital is large next to what labor earns, his position is weak.
Castigliola v. Commissioner, T.C. Memo. 2017-62, involved a member-managed Mississippi PLLC. Management was vested in each member, all of them made the borrowing and hiring decisions, and the court held none could be a limited partner; with equal rights, each stood where a general partner would. New Mexico’s default points the same way: unless the articles name managers, management “shall be vested in the members” (NMSA 1978, § 53-19-15). I often see small LLCs here formed on default articles, so even a silent member may hold management power.
The passive member is harder. Denham describes Hardy v. Commissioner, T.C. Memo. 2017-16, where a surgeon with a minority stake in a surgery center, no management role, and a share driven by facility fees was held to receive it as an investor. Labels do not decide it; New Mexico even lets a true limited partner join in management and keep liability protection (NMSA 1978, § 54-2A-303).
What could Wade’s self-employment tax exposure be for 2023 through 2025?
Illustration only. Assume a $210,000 share for 2025 and no guaranteed payment. Under § 1402(a)(12), net earnings are 92.35 percent of that, or $193,935. The 12.4 percent tax stops at the 2025 wage base of $176,100 (Social Security Administration), producing $21,836, and 2.9 percent on everything adds $5,624, for $27,461. The extra 0.9 percent Medicare tax starts above $200,000, or $250,000 on a joint return (§ 1401(b)(2)), so it does not reach him.
Half, $13,730, is deductible under 26 U.S.C. § 164(f), lowering federal adjusted gross income, where New Mexico base income starts (NMSA 1978, § 7-2-2). With the same share in 2023 and 2024, when the bases were $160,200 and $168,600, the tax is $25,489 and $26,531. Three years total about $79,500 before interest, partly offset by the deductions.
A 20 percent member who contributed cash and does no work would have a $105,000 share. Taxed, it carries $14,836 a year; excluded, nothing.
How does a BBA partnership audit reach self-employment tax, and what is the exposure?
All three appeals arose under TEFRA, the pre-2018 regime. For later years, the BBA partnership audit rules (26 U.S.C. §§ 6221 to 6241) give a partnership representative “sole authority” (§ 6223(a)), and the entity generally pays any imputed underpayment (§ 6225(a)). But Treas. Reg. § 301.6241-6(a)(1) says the regime “only applies to tax imposed by chapter 1,” which leaves out self-employment tax; the IRS may adjust for it in a separate proceeding, taking any BBA determinations into account. My reading is that Wade’s tax would be assessed against him personally. Partnerships issuing 100 or fewer K-1s to eligible partners may also elect out on a timely return (§ 6221(b)).
The IRS’s “SECA tax” compliance campaign, active since March 2018, targets service partners, LLC members included. Assessment generally must come within three years after filing (26 U.S.C. § 6501(a)), so a 2023 return filed by April 15, 2024 stays open until April 15, 2027. A 20 percent penalty can apply (§ 6662). The Castigliola lawyers avoided it under § 6664(c)(1) by relying on a veteran CPA before Renkemeyer, a defense that gets harder for recent years.
Going forward, owners usually weigh guaranteed payments sized to the work against an S corporation election with wages (see the firm’s post on LLC versus S corporation in New Mexico). Some instead split capital from management through manager-managed articles.
| Member type | Likely result under Soroban | What to document | Risk level |
|---|---|---|---|
| Full-time member-manager | No exclusion; whole share is self-employment income | Hours and duties usually confirm the result | High |
| Part-time member working in the field | Likely no exclusion if the work drives profit | Hours, duties, link between share and services | High to moderate |
| Passive member, member-managed LLC | Uncertain; statutory management rights cut against it | No role in decisions; capital at risk | Moderate |
| Passive capital member, manager-managed LLC | Exclusion plausible | Articles naming managers; share tied to capital | Lower |
| Limited partner in a New Mexico LP | Exclusion only if not managing in fact | Actual conduct, not the agreement’s label | Depends on role |
Frequently Asked Questions
Is an LLC member a limited partner for self-employment tax?
Not automatically. The Tax Court asks whether the member functions like one. Members who run the business generally owe it on their full share.
Is a New Mexico taxpayer bound by the Soroban appeal?
Not directly, since New Mexico appeals go to the Tenth Circuit. But the Tax Court applies its own Soroban rule when the Tenth Circuit has not spoken, and it has not.
How many hours can a member work and still claim the exclusion?
No number controls. The 500-hour test in the 1997 proposed regulations was never adopted, and the Second Circuit described its test as depending on the totality of the circumstances.
Do guaranteed payments make the rest of the K-1 share exempt?
No. Guaranteed payments for services are self-employment income on their own terms. In Castigliola the members paid tax on market-rate guaranteed payments and still owed it on the rest of their shares.
Can the IRS still assess self-employment tax for 2023?
Generally yes, if the return was filed in 2024. The three-year period under § 6501(a) runs from filing, and an early return counts as filed on its due date.
How North Star Law Firm Can Help
North Star Law Firm advises New Mexico owners on business entity selection and other tax law questions, and represents members in IRS audits and Tax Court litigation when self-employment tax is in dispute.
Phillip Zagotti, JD/CPA, represents taxpayers before the IRS and the U.S. Tax Court and is admitted to the U.S. District Court and Bankruptcy Court for the District of New Mexico. The firm works alongside New Mexico-licensed counsel on state-law questions. If your K-1 shows no self-employment income and you spend your days running the business, contact North Star Law Firm.








