ERISA Fiduciary-Duty Claims Are Garmon-Barred When Liability Turns on an Unresolved NLRA Status-Quo Duty

I. Introduction

In Rieth-Riley Construction Co. v. Operating Engineers Local 324 (6th Cir. Apr. 3, 2026), an employer (Rieth-Riley Construction Co., Inc.) and several employees sued the trustees and administrators of multiple union-affiliated fringe-benefit funds under ERISA, alleging breach of fiduciary duties after the funds refused to accept ongoing contributions. The refusal arose in the aftermath of a terminated collective bargaining agreement (CBA), during a period in which the employer claimed the NLRA required both sides to maintain the “status quo” while bargaining for a successor agreement.

The central jurisdictional issue was whether the plaintiffs could litigate fiduciary-duty claims under ERISA in federal court when their theory of breach depended on establishing that the funds had an NLRA “status quo” obligation—an issue that would typically fall within the National Labor Relations Board’s (NLRB) primary domain under the San Diego Building Trades Council v. Garmon doctrine.

II. Summary of the Opinion

The Sixth Circuit affirmed dismissal for lack of subject-matter jurisdiction, holding that the plaintiffs’ ERISA claims were precluded by the Garmon doctrine because the alleged wrongdoing was “arguably subject” to NLRA §§ 7 or 8 and the claims, as pled, could succeed only by proving an NLRA violation (i.e., that the funds had a statutory status-quo duty to accept contributions).

The court also affirmed denial of preliminary injunctive relief (no likelihood of success given Garmon) and affirmed denial of leave to amend as futile because the proposed amended complaint still required resolution of the same disputed NLRA status-quo issue.

Judge Hermandorfer concurred, agreeing that Garmon applies under existing precedent but questioning Garmon’s “preemption” label and its jurisdiction-stripping characterization when federal claims are brought in federal court, urging caution against expanding the doctrine beyond its proper scope.

III. Analysis

A. Precedents Cited

1. Core Garmon framework and “arguably subject” standard

  • San Diego Building Trades Council v. Garmon, 359 U.S. 236 (1959): The foundation. When conduct is “arguably subject” to NLRA § 7 or § 8, courts must defer to the NLRB to avoid interference with national labor policy. The Sixth Circuit treated the plaintiffs’ theory as landing in Garmon’s heartland because it required deciding whether the funds’ refusal to accept contributions was arguably an unfair labor practice.
  • Trollinger v. Tyson Foods, Inc., 370 F.3d 602 (6th Cir. 2004): The Sixth Circuit’s modern articulation of Garmon and its exceptions, including the “independent federal remedy” exception. The panel relied on Trollinger for the rule that a claim is not “collateral” when it can succeed “only if” NLRA violations are established.
  • Glacier Nw., Inc. v. Int'l Bhd. of Teamsters Loc. 174, 598 U.S. 771 (2023): Cited to emphasize that the “arguably subject” inquiry focuses on whether the NLRA arguably protects or prohibits the conduct at issue.
  • Kaiser Steel Corp. v. Mullins, 455 U.S. 72 (1982): Reinforces the Board’s primary role in defining unfair labor practices and appears both in the majority opinion (for deference principles and the collateral-issues concept) and the concurrence (as part of the exception discussion).
  • Knafel v. Pepsi Cola Bottlers of Akron, Inc., 850 F.2d 1155 (6th Cir. 1988): Cited for the notion that the NLRB has primary jurisdiction to determine unfair labor practices.
  • Moreno v. UtiliQuest, LLC, 29 F.4th 567 (9th Cir. 2022): Used to reject the argument that Garmon depends on the availability of the plaintiff’s particular remedy before the Board; the doctrine is about conflict with federal labor policy, not forum identity for the non-NLRA claim.
  • Retail Prop. Tr. v. United Bhd. of Carpenters & Joiners of Am., 768 F.3d 938 (9th Cir. 2014): Cited for the policy focus—Garmon protects against conflicts with national labor policy.

2. The independent federal remedy exception (and its limits)

  • Connell Constr. Co. v. Plumbers & Steamfitters Loc. Union No. 100, 421 U.S. 616 (1975): Source for the principle that federal courts may decide labor-law questions that arise as collateral issues in suits under independent federal remedies.
  • Commc'ns Workers of Am. v. Beck, 487 U.S. 735 (1988): Quoted to warn against “circumvent[ing] the primary jurisdiction of the NLRB” by re-casting NLRA-based claims under another statute.
  • Pulte Homes, Inc. v. Laborers' Int'l Union of N. Am., 648 F.3d 295 (6th Cir. 2011): Provided the Sixth Circuit’s test that the independent-remedy exception applies only when the plaintiff can prove the claim without establishing an NLRA violation.

3. ERISA and the NLRA status-quo bargaining duty

  • Laborers Health & Wellness Tr. Fund for N. Ca. v. Advanced Lightweight Concrete Co., Inc., 484 U.S. 539 (1988): The key ERISA/NLRA interaction precedent. The Supreme Court applied Garmon to ERISA claims where resolution turned on an arguable NLRA unfair labor practice— demonstrating that ERISA’s federal status does not immunize claims from Garmon’s Board-first allocation.
  • Litton Fin. Printing Div. v. NLRB, 501 U.S. 190 (1991): Used to describe the post-expiration duty to maintain the status quo as to terms and conditions of employment while bargaining continues.
  • Operating Eng'rs' Loc. 324 Fringe Benefit Funds v. Rieth-Riley Constr. Co., Inc., 43 F.4th 617 (6th Cir. 2022) (Rieth-Riley I): Cited for the status-quo principle as applied to bargained-for contributions to benefit funds and for the proposition that stopping contributions can constitute a unilateral change (and thus an unfair labor practice).
  • Rieth-Riley Constr. Co., Inc. v. NLRB, 114 F.4th 519 (6th Cir. 2024) (Rieth-Riley II): Provided the panel’s background on NLRA §§ 7 and 8 and the duty to bargain collectively.
  • Hendrickson USA, LLC v. NLRB, 932 F.3d 465 (6th Cir. 2019): Quoted (via Rieth-Riley II) for the basic articulation of § 7 rights.
  • RiverStone Grp., Inc., v. Midwest Operating Eng'rs' Fringe Benefit Funds, 33 F.4th 424 (7th Cir. 2022): A reinforcing circuit analogue applying Garmon in the ERISA-fringe-fund context where NLRA questions are embedded and disputed.

4. Preliminary injunction and amendment standards (procedural but consequential)

  • Winter v. Nat. Res. Def. Council, Inc., 555 U.S. 7 (2008): The four-factor preliminary injunction test.
  • O'Toole v. O'Connor, 802 F.3d 783 (6th Cir. 2015) and Gonzalez v. Nat'l Bd. of Med. Exam'rs, 225 F.3d 620 (6th Cir. 2000): Likelihood of success is usually dispositive; here it failed because Garmon barred the claims.
  • Stryker Emp. Co. v. Abbas, 60 F.4th 372 (6th Cir. 2023) and Obama for Am. v. Husted, 697 F.3d 423 (6th Cir. 2012): Standards of review for injunction denials.
  • Morse v. McWhorter, 290 F.3d 795 (6th Cir. 2002); Keweenaw Bay Indian Cmty. v. Michigan, 11 F.3d 1341 (6th Cir. 1993); Foman v. Davis, 371 U.S. 178 (1962): Rule 15’s liberal amendment policy and grounds for denial, especially futility.
  • Graveline v. Benson, 992 F.3d 524 (6th Cir. 2021); Bowling v. Pfizer, Inc., 102 F.3d 777 (6th Cir. 1996); Miller v. Champion Enters. Inc., 346 F.3d 660 (6th Cir. 2003): Review standards and de novo review of futility.

5. The concurrence’s jurisdictional critique and administrative-law signals

Judge Hermandorfer’s concurrence is not the holding, but it frames future litigation and doctrinal pressure points, drawing on:

  • Susan B. Anthony List v. Driehaus, 573 U.S. 149 (2014): The federal courts’ “virtually unflagging” obligation to decide cases within jurisdiction.
  • Baker v. IBP, Inc., 357 F.3d 685 (7th Cir. 2004) and General Motors, LLC v. FCA US, LLC, 44 F.4th 548 (6th Cir. 2022): The idea that “federal statutes do not ‘preempt’ other federal statutes,” suggesting “Garmon preemption” is a misnomer for federal claims.
  • New Heights Farm I, LLC v. Great Am. Ins. Co., 119 F.4th 455 (6th Cir. 2024); United States v. Kwai Fun Wong, 575 U.S. 402 (2015); Harrow v. Dep't of Def., 601 U.S. 480 (2024): The “clear statement” principle for jurisdiction stripping.
  • Hamer v. Neighborhood Hous. Servs. of Chi., 583 U.S. 17 (2017): Preference for clear jurisdictional rules.
  • United States v. Haun, 124 F.3d 745 (6th Cir. 1997): Limits of primary jurisdiction if no administrative forum is available.
  • Sears, Roebuck & Co. v. S.D. Cnty. Dist. Council of Carpenters, 436 U.S. 180 (1978): Used for the “reasonable opportunity” to secure a Board decision and caution against mechanistic Garmon application.
  • Axon Enter., Inc. v. FTC, 598 U.S. 175 (2023) and Gibson v. Berryhill, 411 U.S. 564 (1973): Situations where structural constitutional issues may belong in district court despite agency processes.
  • Loper Bright Enterprises v. Raimondo, 603 U.S. 369 (2024): Courts’ duty to exercise independent judgment in statutory interpretation, raising questions about shunting statutory meaning to agencies.
  • SEC v. Jarkesy, 603 U.S. 109 (2024) and Int'l Union of Operating Eng'rs, Stationary Eng'rs, Loc. 39 v. NLRB, 155 F.4th 1023 (9th Cir. 2025): Signals about Article III/jury-trial constraints for agency adjudication of legal-in-nature claims.
  • Carr v. Saul, 593 U.S. 83 (2021); Smith v. SEC, 2026 WL 850806 (6th Cir. 2026); Fallick v. Nationwide Mut. Ins. Co., 162 F.3d 410 (6th Cir. 1998); John S. Griffith Constr. Co. v. United Bhd. of Carpenters & Joiners of S. Cal., 785 F.2d 706 (9th Cir. 1986): Cited to suggest possible “futility”-type concerns in exhaustion/agency-first regimes, and to highlight edge cases where Board access is practically unavailable.

B. Legal Reasoning

1. Why Garmon applied despite the plaintiffs pleading ERISA (a federal statute)

The court rejected the plaintiffs’ attempt to confine Garmon to state-law claims. Relying on Trollinger and Kaiser Steel Corp. v. Mullins, it stated that federal courts must also defer when the underlying conduct is arguably protected or prohibited by the NLRA—unless an exception applies. The court underscored that the Supreme Court has applied Garmon to ERISA itself, citing Laborers Health & Wellness Tr. Fund for N. Ca. v. Advanced Lightweight Concrete Co., Inc..

2. “Arguably subject” turned on the conduct and labor-policy conflict, not on whether the NLRB could hear ERISA

The plaintiffs argued Garmon should not apply because the NLRB lacks jurisdiction to adjudicate ERISA fiduciary-duty claims. The Sixth Circuit called this a category mistake: the “arguably subject” inquiry asks whether the challenged conduct is arguably protected or prohibited by NLRA §§ 7 or 8 (Glacier Nw., Inc. v. Int'l Bhd. of Teamsters Loc. 174; Garmon), not whether the specific cause of action is one the NLRB can adjudicate. The court emphasized labor-policy uniformity and agency expertise (citing Nw. Ohio Adm'rs, Inc. v. Walcher & Fox, Inc. via Trollinger).

3. The independent federal remedy exception failed because NLRA violation was not “collateral”—it was essential

The case turned on pleading theory. The plaintiffs did not merely allege: “ERISA requires trustees to accept lawful contributions.” They alleged: the trustees breached ERISA because the NLRA itself imposed a “status quo” duty on the funds to accept contributions during bargaining. Because the ERISA breach could be established “only if” the court first resolved the contested NLRA question, the labor-law issue was not collateral (Trollinger; Commc'ns Workers of Am. v. Beck).

This is the opinion’s key operational rule: when the ERISA claim requires the court to decide whether a party’s conduct is an NLRA unfair labor practice, the plaintiff is effectively re-packaging an NLRA dispute inside ERISA, triggering Garmon and routing the matter to the NLRB.

4. Consequences for preliminary injunctions and amendment practice

Once the panel affirmed Garmon’s bar, it straightforwardly affirmed denial of preliminary injunctions under Winter v. Nat. Res. Def. Council, Inc. because likelihood of success was absent (O'Toole v. O'Connor; Gonzalez v. Nat'l Bd. of Med. Exam'rs).

Similarly, leave to amend was futile under Rule 15 principles (Foman v. Davis) because the proposed amended complaint still depended on the same unresolved NLRA status-quo duty question.

C. Impact

1. Litigation-channeling: NLRA disputes cannot be litigated “through ERISA”

The decision strengthens a clear channeling signal in the Sixth Circuit: parties cannot use ERISA fiduciary-duty theories to obtain district-court resolution of contested NLRA status-quo obligations. If success requires proving that conduct violates §§ 7 or 8, the dispute belongs at the NLRB first.

2. Pleading discipline: ERISA claims must be provable without establishing an NLRA violation

The opinion incentivizes careful pleading and theory selection. It suggests that ERISA claims might proceed if they are genuinely independent—i.e., provable without adjudicating a contested NLRA duty. The concurrence expressly cautions that the decision should not be read to foreclose “distinct ERISA claims that do not turn on the Funds’ alleged NLRA obligations.”

3. Doctrinal pressure: the concurrence flags future challenges to “Garmon as jurisdiction-stripping”

While not altering the outcome, the concurrence is significant in identifying tensions between Garmon and modern jurisdictional/administrative-law principles (e.g., “federal statutes do not ‘preempt’ other federal statutes,” the “clear statement” rule for jurisdiction stripping, and post-Loper Bright judicial interpretation duties). Future litigants may cite this concurrence to argue for narrower Garmon application, reframing it as a prudential sequencing doctrine rather than a true subject-matter jurisdiction bar—though the panel applied existing Sixth Circuit precedent as binding.

IV. Complex Concepts Simplified

  • Garmon “preemption” (more accurately, Board-first deference): A judge-made rule directing courts to let the NLRB decide, in the first instance, disputes over conduct arguably protected or prohibited by NLRA §§ 7 or 8, to preserve uniform labor policy and avoid conflicting rulings.
  • “Arguably subject” to the NLRA: The threshold is intentionally low—if the conduct could plausibly be an unfair labor practice (or protected activity), courts generally step back.
  • Status-quo duty after CBA expiration: During bargaining for a new agreement, parties often must maintain existing terms and conditions (including benefit contributions) and cannot make unilateral changes (Litton Fin. Printing Div. v. NLRB; Operating Eng'rs' Loc. 324 Fringe Benefit Funds v. Rieth-Riley Constr. Co., Inc.).
  • Independent federal remedy exception: Courts may decide labor-law issues only if they arise as truly collateral to an independent federal claim—meaning the plaintiff can win without proving an NLRA violation (Pulte Homes, Inc. v. Laborers' Int'l Union of N. Am.).
  • ERISA fiduciary duties (loyalty and prudence): Trustees must act for plan participants’ benefit and with due care. But this case holds ERISA cannot be used as a vehicle to decide a disputed NLRA duty that is essential to liability.
  • Futility of amendment: Even under liberal Rule 15 standards, courts deny amendment when the new pleading would still be dismissed for the same legal reason.

V. Conclusion

The Sixth Circuit’s decision establishes a practical and consequential rule for ERISA-and-labor disputes: when plaintiffs plead ERISA fiduciary-duty claims in a way that makes success depend on proving an unresolved NLRA status-quo obligation (and thus an arguable unfair labor practice), Garmon requires federal courts to defer to the NLRB and dismiss. The opinion reinforces the limits of the independent federal remedy exception and underscores that labeling a claim “ERISA” does not avoid labor-law channeling principles. At the same time, the concurrence signals doctrinal unease with treating Garmon as a jurisdiction-stripping “preemption” rule for federal claims—foreshadowing future efforts to narrow or recharacterize Garmon while leaving intact, for now, its controlling force in the Sixth Circuit.