Diversity Jurisdiction: When Federal Courts Hear State Law Claims

Diversity jurisdiction is one of two primary pathways by which a dispute rooted entirely in state law can be heard by a federal district court rather than a state tribunal. Grounded in Article III of the U.S. Constitution and codified at 28 U.S.C. § 1332, it exists to address a specific concern: that state courts might favor local litigants over out-of-state parties. This page covers the statutory definition of diversity jurisdiction, the procedural mechanics that activate it, the fact patterns most likely to trigger it, and the boundary rules that determine whether a case qualifies.

Definition and scope

Diversity jurisdiction grants federal district courts authority to hear civil cases between citizens of different U.S. states — or between U.S. citizens and foreign nationals — when the amount in controversy exceeds $75,000, exclusive of interest and costs (28 U.S.C. § 1332). The $75,000 threshold has remained unchanged since Congress raised it from $50,000 in the Federal Courts Improvement Act of 1996 (Pub. L. 104-317).

Two independent requirements must both be satisfied:

  1. Complete diversity of citizenship — No plaintiff can share state citizenship with any defendant at the time the complaint is filed.
  2. Amount in controversy — The plaintiff's good-faith demand must exceed $75,000.

If either requirement fails, the federal court lacks subject-matter jurisdiction and must dismiss or remand the case regardless of how far litigation has progressed. As explained in the federal court jurisdiction explained reference, diversity jurisdiction is entirely distinct from federal question jurisdiction, which arises from claims based on the U.S. Constitution, federal statutes, or treaties.

How it works

Establishing citizenship

For individuals, citizenship means domicile — the state where a person both resides and intends to remain indefinitely. A party can have only one domicile at any given moment, meaning a person who maintains residences in two states is a citizen of only one for diversity purposes.

For corporations, 28 U.S.C. § 1332(c)(1) establishes a dual-state rule: a corporation is deemed a citizen of both the state where it is incorporated and the state where it maintains its principal place of business. The U.S. Supreme Court clarified "principal place of business" in Hertz Corp. v. Friend, 559 U.S. 77 (2010), holding it means the corporation's "nerve center" — typically the state where high-level officers direct, control, and coordinate the corporation's activities.

For unincorporated entities such as partnerships and limited liability companies, courts apply citizenship to every member of the entity, not to the entity itself. A single LLC member sharing citizenship with the opposing party destroys complete diversity.

The amount-in-controversy calculation

Courts generally accept the plaintiff's alleged damages at face value unless it is legally certain that the claim cannot exceed $75,000. The calculation can aggregate multiple claims by a single plaintiff against a single defendant but ordinarily cannot aggregate separate plaintiffs' claims to reach the threshold (established in Snyder v. Harris, 394 U.S. 332 (1969)).

Removal from state court

A defendant sued in state court on a diversity-qualifying claim may remove the case to the federal district court for the district embracing the state court's location under 28 U.S.C. § 1441. One major restriction applies: a defendant who is a citizen of the state in which the action is filed cannot invoke the diversity removal right — the so-called "home-state defendant" rule codified at 28 U.S.C. § 1441(b)(2). Removal must occur within 30 days of receiving the initial pleading, or within 30 days of an amended pleading that first establishes diversity grounds.

Common scenarios

Diversity jurisdiction appears most frequently in four recurring fact patterns:

  1. Interstate tort claims — A driver from Ohio injures a pedestrian in Indiana. The injured pedestrian, a citizen of Indiana, sues the Ohio driver and the Ohio trucking company in federal court, alleging damages exceeding $75,000 in medical and lost-wage costs.

  2. Breach of contract between businesses in different states — A California software vendor and a New York retailer dispute a $200,000 software licensing agreement. Because no party shares citizenship and the amount clears the statutory floor, the case may proceed in federal district court.

  3. Products liability — A consumer in Pennsylvania sues a product manufacturer incorporated in Delaware with its principal place of business in Michigan. The claim exceeds $75,000; complete diversity is present.

  4. Insurance disputes — A policyholder in Florida disputes a claim denial by an insurer incorporated in Connecticut. The amount in controversy, reflecting the policy value, exceeds the threshold.

In each scenario, the underlying substantive law remains state law. The federal court applies the choice-of-law rules and substantive law of the state in which it sits, consistent with Erie Railroad Co. v. Tompkins, 304 U.S. 64 (1938).

Decision boundaries

Diversity jurisdiction vs. federal question jurisdiction — Federal question jurisdiction under 28 U.S.C. § 1331 requires no minimum dollar amount and no citizenship differential; a single claim arising under federal law suffices. Diversity jurisdiction, by contrast, is purely about the parties' citizenship and the size of the dispute — the underlying law is state law throughout. A plaintiff relying on diversity jurisdiction cannot also benefit from the absence of a dollar-amount requirement that would apply under federal question jurisdiction.

The domestic relations and probate exceptions — Federal courts applying diversity jurisdiction have long declined to exercise that authority over domestic relations matters (divorce, alimony, child custody) and probate proceedings. The Supreme Court refined the domestic relations exception in Ankenbrandt v. Richards, 504 U.S. 689 (1992), confining it to cases seeking issuance or modification of a divorce, alimony, or child-custody decree — not tort claims between family members, which can proceed under diversity.

Fraudulent joinder — A plaintiff who adds a non-diverse defendant solely to defeat diversity jurisdiction may find that defendant disregarded. Courts apply a fraudulent joinder standard: if there is no reasonable basis in fact or law to state a claim against the non-diverse defendant, that defendant's citizenship is ignored for diversity purposes, preserving federal jurisdiction.

Supplemental jurisdiction interaction — Once a federal court acquires diversity jurisdiction over a core claim, it may exercise supplemental jurisdiction under 28 U.S.C. § 1367 over related state-law claims that would not independently qualify — for example, a counterclaim below the $75,000 threshold. The federal courts' general subject-matter framework, including where diversity fits within the broader subject-matter jurisdiction analysis, governs how this interplay operates.

For a broader orientation to how these rules operate across the full federal system, the federal courts authority home provides a structured entry point to related jurisdictional and procedural topics.