Sixth Circuit: Diversity Jurisdiction Over Lloyd’s Syndicates Requires Citizenship of Each Underwriting Name (Not the Managing Agent)

I. Introduction

In Julie Schulz Halbower v. Hiscox Syndicate 33 of Lloyd's of London (6th Cir. May 29, 2026), the Court of Appeals addressed a threshold problem that often lurks in litigation involving Lloyd’s of London: how to plead and prove diversity jurisdiction when the defendant is a Lloyd’s syndicate.

The plaintiff, Julie Schulz Halbower (trustee of the Halbower Legacy Trust), sued Hiscox Syndicate 33 in Michigan state court after a fire destroyed a home and allegedly uninsured artwork. Hiscox removed the case to federal court based on diversity jurisdiction, and the district court dismissed the complaint on the merits.

On appeal, the Sixth Circuit did not reach the insurance-coverage merits. Instead, it held the record did not adequately establish diversity jurisdiction because the citizenship of the syndicate’s underwriting “Names” had not been pleaded or proven. The court vacated the dismissal and remanded for jurisdictional discovery.

II. Summary of the Opinion

  • The court reiterated its independent duty to confirm subject-matter jurisdiction even if the parties do not challenge it, citing Arbaugh v. Y & H Corp..
  • For diversity purposes, the trust’s citizenship followed the trustee’s citizenship (New Hampshire), citing Navarro Sav. Ass'n v. Lee and Homfeld II, L.L.C. v. Comair Holdings, Inc..
  • The court treated the Lloyd’s syndicate as an unincorporated association whose citizenship depends on each member’s citizenship, following Carden v. Arkoma Assocs. and Delay v. Rosenthal Collins Grp., LLC.
  • It rejected the insurer’s argument that Certain Interested Underwriters v. Layne allows jurisdiction to be determined solely by the managing agent’s citizenship.
  • Because the district court relied on the managing agent’s citizenship and the record did not identify the citizenship of each underwriting Name, the court vacated and remanded for further proceedings.

Judge Bush concurred in the judgment but disagreed with the majority’s reasoning, favoring an approach grounded in Layne and state agency/real-party-in-interest principles.

III. Analysis

A. Precedents Cited

1. The court’s obligation to verify jurisdiction

The panel began with the premise that appellate courts must confirm jurisdiction before addressing merits issues, relying on Sherrod v. Wal-Mart Stores, Inc. and the Supreme Court’s instruction in Arbaugh v. Y & H Corp. that courts have an “independent obligation” to assure themselves of subject-matter jurisdiction. This framing is pivotal: it authorizes the court to upend a merits dismissal and reopen the record solely to test jurisdiction.

2. Complete diversity and the time-of-removal rule

The court anchored the diversity standard in Strawbridge v. Curtiss (complete diversity) and applied Sixth Circuit authority on citizenship overlap (Peters v. Fair). It fixed the citizenship inquiry at the moment of removal, invoking Rogers v. Wal-Mart Stores, Inc. and Ahearn v. Charter Township of Bloomfield. These cases matter because Lloyd’s membership can be large and dynamic; pegging citizenship to removal prevents later shifts from controlling.

3. Trust citizenship

For the plaintiff trust, the court followed Navarro Sav. Ass'n v. Lee and Homfeld II, L.L.C. v. Comair Holdings, Inc. to treat the trust as a citizen of the trustee’s state (New Hampshire). This was the “easy” side of the diversity equation.

4. Unincorporated associations: member-by-member citizenship

The central jurisdictional move rested on Carden v. Arkoma Assocs., which requires courts to determine the citizenship of unincorporated associations by the citizenship of all members, absent a statutory rule like 28 U.S.C. § 1332(c)(1) for corporations. The panel also cited Delay v. Rosenthal Collins Grp., LLC to confirm the Sixth Circuit’s adherence to this bright-line approach.

Importantly, the court described Hiscox Syndicate 33 as functioning “in ways similar to an unincorporated association,” and thus concluded that the citizenship of each underwriting “Name” must be considered.

5. Lloyd’s-specific circuit authority (supporting the majority’s approach)

The court aligned itself with other circuits requiring pleading of each Name’s citizenship: Ind. Gas Co. v. Home Ins. Co., Underwriters v. Osting-Schwinn, and E.R. Squibb & Sons, Inc. v. Accident & Cas. Ins. Co.. These cases directly informed the opinion’s conclusion that a Lloyd’s syndicate’s citizenship tracks the citizenship of its Names.

The opinion also noted that some courts have read Certain Interested Underwriters v. Layne in ways inconsistent with Carden, and it referenced criticism of Layne in Ind. Gas Co. v. Home Ins. Co. and interpretive distinctions in E.R. Squibb & Sons, Inc. v. Accident & Cas. Ins. Co. (quoting N. Tr. Co. v. Bunge Corp.).

6. Remand for development of jurisdictional facts

The decision to remand for jurisdictional development was supported by analogies to remands in other jurisdictional contexts, including Hertz Corp. v. Friend and V & M Star, LP v. Centimark Corp.. The panel’s message: where citizenship facts are missing and material, the proper remedy is to vacate merits action and remand to build a record.

7. How Certain Interested Underwriters v. Layne was treated

Hiscox argued that Certain Interested Underwriters v. Layne permits focusing on the Lloyd’s managing agent (here, Hiscox Syndicate Limited). The majority rejected that reading, explaining that Layne involved an unusual policy not naming a syndicate and instead naming “Certain Interested Underwriters at Lloyd's of London.” In that setting, the court in Layne used a Federal Rule of Civil Procedure 17(a) real-party-in-interest lens and treated the listed “active-underwriters” as the relevant parties.

The majority treated Layne as narrow: it does not establish a general rule that a managing agent’s citizenship controls where a syndicate is sued and the syndicate’s Names are the entities ultimately liable.

8. The concurring opinion’s authorities

Judge Bush’s concurrence relied heavily on Certain Interested Underwriters of Lloyd's, London, England v. Layne and on the concept that jurisdiction should focus on the “real part[ies] to the controversy,” quoting Wormley v. Wormley and Carden v. Arkoma Assocs. (as quoted in Layne). It invoked Michigan agency-law cases—Dodge v. Blood and Old Ben Coal Co. v. Universal Coal Co.—to explain that, when an undisclosed principal exists, plaintiff’s choice to sue principal rather than agent affects liability, and thus the real-party inquiry. It contrasted disclosed-principal rules from Howard & Howard Att'ys P.L.L.C. v. Jabbour.

The concurrence also cited Sixth Circuit cases emphasizing real-party-in-interest and liability focus (Lukowski v. CSX Transp., Inc.; In re M.T.G., Inc.), and it relied on Detroit Pure Milk Co. v. Patterson for Michigan’s definition of “undisclosed principal.” These authorities supported Judge Bush’s view that state agency law can be jurisdiction-relevant in Lloyd’s cases.

9. Other cited Lloyd’s background cases in the concurrence

The concurrence cited Advani Enters., Inc. v. Underwriters at Lloyds and Liberty Syndicates at Lloyd's v. Walnut Advisory Corp. for Lloyd’s structural propositions, and Cox v. Total Quality Logistics, Inc. as a reminder that coverage disputes ordinarily do not present federal questions.

10. Intra-circuit stare decisis

The majority emphasized it could not “dislodge” Layne even if controversial, citing United States v. Ferguson and Salmi v. Sec'y of Health & Hum. Servs.. This framed the opinion as harmonizing with—rather than overruling—Layne by distinguishing it.

C. Impact

1. Pleading burden and removal strategy

The opinion raises the bar for defendants removing Lloyd’s cases in the Sixth Circuit: it will not be enough to allege citizenship of a managing agent. Parties must be prepared to identify each underwriting Name and plead (and, if challenged, prove) each Name’s citizenship at the time of removal. This can be practically difficult given Lloyd’s structure, but the court treated that difficulty as subordinate to Carden’s rule.

2. Jurisdictional discovery becomes central in Lloyd’s litigation

By remanding for “further jurisdictional discovery,” the court signals that district courts should permit factual development where Names’ citizenship is unknown. Expect more early motion practice on jurisdiction, targeted discovery requests to brokers/agents/managing agents, and potential protective-order litigation given the sensitivity of membership and investor information.

3. Increased likelihood of state-court adjudication

If any Name shares citizenship with the plaintiff, complete diversity fails and the case must proceed in state court. Given the large number of Names in some syndicates, the probability of a citizenship “collision” increases. The decision therefore may reduce Lloyd’s syndicates’ ability to access federal forums via diversity in the Sixth Circuit.

4. Doctrinal clarity inside the circuit (but with an unresolved tension)

The majority narrows Certain Interested Underwriters v. Layne to its unusual policy posture. Yet the concurrence illustrates ongoing tension about whether “real party in interest” analysis, driven by state agency law, should shape the jurisdictional inquiry. Future panels may confront edge cases that more directly test the boundary between Layne-style agency analysis and Carden-style entity analysis.

IV. Complex Concepts Simplified

Diversity (and alienage) jurisdiction; “complete diversity”
Federal courts may hear certain state-law disputes if all plaintiffs are citizens of different states than all defendants. Under Strawbridge v. Curtiss, even one overlap defeats jurisdiction. Under 28 U.S.C. § 1332(a)(2), jurisdiction can also exist between a U.S. citizen and a “citizen or subject of a foreign state,” but complete-diversity principles still apply.
Unincorporated association citizenship
Unlike corporations (which have statutory citizenship rules), an unincorporated association’s citizenship is the citizenship of all its members, per Carden v. Arkoma Assocs..
Lloyd’s “syndicate,” “Names,” and “managing agent”
A Lloyd’s syndicate is an administrative underwriting arrangement; the actual risk-bearers are “Names” (members) who are severally liable, meaning each pays only its share. The “managing agent” runs operations and places risks but generally is not itself on the hook for the loss.
Rule 17(a) “real party in interest”
Rule 17(a) requires suit in the name of the party entitled to enforce the right. The majority emphasized this rule is not itself jurisdictional (as Layne noted), and separated the “who can sue” question from the “do we have jurisdiction” question.
Vacate and remand for jurisdictional discovery
“Vacate” nullifies the district court’s judgment; “remand” sends the case back for additional proceedings—here, to gather facts needed to decide jurisdiction.

V. Conclusion

The Sixth Circuit’s decision establishes a practical jurisdictional rule for Lloyd’s litigation in this circuit: when a Lloyd’s syndicate is a party, diversity jurisdiction turns on the citizenship of each underwriting Name, not the managing agent. By vacating a merits dismissal and ordering jurisdictional discovery, the court underscored that federal courts must confirm jurisdiction first—even where both sides assume it exists—and that Carden’s member-citizenship principle governs modern disputes involving Lloyd’s syndicates.

The separate concurrence highlights an alternative, state-law-driven route through Layne and agency principles, foreshadowing continued debate over how best to translate Lloyd’s distinctive structure into U.S. jurisdictional doctrine. For now, litigants in the Sixth Circuit should expect rigorous, Name-by-Name citizenship scrutiny before federal courts will proceed to the merits in Lloyd’s coverage disputes.