Diversity Jurisdiction: Requirements and Federal Thresholds

Diversity jurisdiction is one of the two primary bases on which a federal district court can hear a civil case, the other being federal question jurisdiction. This page covers the statutory requirements for establishing diversity jurisdiction, the constitutional and codified thresholds that govern it, the fact patterns where it typically arises, and the boundary conditions that determine whether a case qualifies or fails. Understanding these rules is essential for any analysis of federal versus state court selection in civil litigation.

Definition and scope

Diversity jurisdiction grants federal district courts authority to adjudicate civil disputes between citizens of different states — or between a U.S. citizen and a foreign citizen — when the amount in controversy exceeds a statutory floor. The constitutional basis is Article III, Section 2 of the U.S. Constitution, which extends judicial power to "Controversies . . . between Citizens of different States." Congress has implemented and narrowed this grant through 28 U.S.C. § 1332, the primary diversity jurisdiction statute administered and interpreted through the federal judiciary.

The rationale for diversity jurisdiction, as recognized by the Federal Judicial Center, is to provide a neutral federal forum and reduce the risk of local bias when parties from different states litigate. Federal courts do not apply federal substantive law in diversity cases; under the Erie doctrine (established in Erie Railroad Co. v. Tompkins, 304 U.S. 64 (1938)), they apply the substantive law of the state in which they sit while following federal procedural rules under the Federal Rules of Civil Procedure.

Two distinct requirements under 28 U.S.C. § 1332 must both be satisfied:

1. Complete diversity of citizenship — no plaintiff may share state citizenship with any defendant.
2. Amount in controversy exceeding amounts that vary by jurisdiction — exclusive of interest and costs, at the time the complaint is filed.

Failure to satisfy either element strips the federal court of subject matter jurisdiction, and the case must be dismissed or remanded to state court.

How it works

Determining citizenship

For individual parties, citizenship means domicile — the state where a person is physically present with intent to remain indefinitely. Residence alone is insufficient (Mas v. Perry, 489 F.2d 1396 (5th Cir. 1974)).

For corporations, 28 U.S.C. § 1332(c)(1) assigns citizenship to both the state of incorporation and the state where the corporation maintains its principal place of business (its "nerve center," per Hertz Corp. v. Friend, 559 U.S. 77 (2010)). A corporation incorporated in Delaware with its primary location in California is a citizen of both states for diversity purposes.

For unincorporated entities such as partnerships and LLCs, citizenship is determined by the citizenship of every member, a rule that can multiply the number of states at issue and defeat diversity.

The complete diversity rule

The complete diversity requirement — derived from Strawbridge v. Curtiss, 7 U.S. (3 Cranch) 267 (1806) — means that if even one plaintiff and one defendant share citizenship in the same state, diversity is entirely destroyed. Congress has created a statutory exception for class actions through the Class Action Fairness Act of 2005 (CAFA), 28 U.S.C. § 1332(d), which requires only minimal diversity (any plaintiff diverse from any defendant) where the aggregate amount in controversy exceeds amounts that vary by jurisdiction and the class has at least 100 members.

Amount in controversy

The amounts that vary by jurisdiction threshold, codified in 28 U.S.C. § 1332(a), is measured by the plaintiff's good-faith claim at the time of filing. In cases removed from state court, the removing defendant must demonstrate by a preponderance of the evidence that the amount exceeds the threshold (Dart Cherokee Basin Operating Co. v. Owens, 574 U.S. 81 (2014)). Aggregation of claims across multiple plaintiffs is generally prohibited unless plaintiffs assert a single, undivided interest.

Common scenarios

Diversity jurisdiction surfaces in a predictable range of civil disputes:

1. Contract disputes — A business incorporated in New York suing a supplier domiciled in Texas for breach of a supply agreement where damages exceed amounts that vary by jurisdiction.
2. Tort claims — An individual injured in an automobile accident in Ohio suing a driver domiciled in Michigan for more than amounts that vary by jurisdiction in damages; this intersects directly with tort law principles.
3. Insurance coverage disputes — An insured in Florida litigating a denied claim against an insurer incorporated in Connecticut and headquartered in Illinois; both states count as the insurer's citizenship.
4. Real property disputes — Disputes over land ownership or title between citizens of different states, provided the value meets the threshold; relevant to property law fundamentals.
5. Class actions under CAFA — Multi-state consumer class actions where aggregate claims surpass amounts that vary by jurisdiction even if individual claims fall below amounts that vary by jurisdiction.

The table below contrasts standard diversity jurisdiction with CAFA diversity jurisdiction:

Decision boundaries

When diversity fails

The following conditions defeat or complicate diversity jurisdiction:

• A shared state of citizenship between any plaintiff and any defendant under the complete diversity rule.
• An amount in controversy at or below amounts that vary by jurisdiction (the threshold is strictly more than, not equal to, amounts that vary by jurisdiction per 28 U.S.C. § 1332(a)).
• An LLC or partnership with a member who shares citizenship with an opposing party.
• Assignment of a claim solely to manufacture diversity, which courts scrutinize under 28 U.S.C. § 1359 to prevent collusive or improper joinder.

Removal and remand

A defendant in a state court action may remove to federal court if diversity exists, under 28 U.S.C. § 1441, within 30 days of receiving the initial pleading. A forum defendant rule under 28 U.S.C. § 1441(b)(2) bars removal when any properly joined defendant is a citizen of the state in which the action was filed. The plaintiff may then move to remand under 28 U.S.C. § 1447(c) if the removal was procedurally or jurisdictionally defective. For a broader look at remand and removal in the context of concurrent jurisdiction, those mechanics interact with both diversity and federal question grounds.

Relation to personal jurisdiction

Diversity jurisdiction addresses only subject matter authority — it does not independently establish personal jurisdiction over the defendant. A federal court hearing a diversity case still requires a constitutionally adequate basis to compel the defendant's appearance, typically governed by the forum state's long-arm statute and the Due Process Clause of the Fourteenth Amendment.

Abstention and state law primacy

Even when diversity jurisdiction is technically present, federal courts may decline to exercise it under abstention doctrines — notably Pullman abstention when a case involves an unsettled question of state law, and Burford abstention when a case implicates complex state regulatory schemes. These doctrines acknowledge that diversity jurisdiction is a pragmatic grant, not a mandate, and that state courts retain primary authority over their own substantive law.

References

• 28 U.S.C. § 1332 — Diversity of Citizenship; Amount in Controversy (Cornell LII)
• 28 U.S.C. § 1441 — Removal of Civil Actions (Cornell LII)
• Federal Judicial Center — Jurisdiction Overview
• Class Action Fairness Act of 2005, Pub. L. 109-2, 28 U.S.C. § 1332(d) (Congress.gov)
• Hertz Corp. v. Friend, 559 U.S. 77 (2010) — Supreme Court of the United States (Justia)
• Dart Cherokee Basin Operating Co. v. Owens, 574 U.S. 81 (2014) — Supreme Court (Justia)
• Erie Railroad Co. v. Tompkins, 304 U.S. 64 (1938) — Supreme Court (Justia)
• Federal Rules of Civil Procedure — U.S. Courts