Diversity Jurisdiction

Diversity Jurisdiction

Diversity jurisdiction is a form of federal subject-matter jurisdiction that allows certain civil cases between citizens of different states, or between U.S. citizens and citizens of foreign countries, to be heard in federal court. Its principal statutory basis is 28 U.S.C. § 1332.

The basic idea is relatively simple: when the parties are citizens of different states and the amount in controversy exceeds the statutory threshold, a federal district court may have jurisdiction even though the lawsuit does not arise under federal law.

But diversity jurisdiction has several technical requirements. The most important are complete diversity of citizenship and an amount in controversy exceeding $75,000, exclusive of interest and costs. The citizenship rules can also become complicated when the parties include corporations, LLCs, partnerships, estates, representatives, or foreign parties.

Cornell Law School’s Legal Information Institute provides a useful overview of diversity jurisdiction, including the requirements of complete diversity and the amount-in-controversy threshold.

Diversity jurisdiction is therefore not simply a rule saying that “people from different states can sue in federal court.” It is a carefully defined statutory jurisdictional framework that operates alongside constitutional limitations, federal procedural rules, and important Supreme Court doctrines.

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What Is Diversity Jurisdiction?

Diversity jurisdiction permits federal courts to hear certain civil disputes in which the parties have the required diversity of citizenship and the amount in controversy satisfies the statutory requirement.

The principal statute is 28 U.S.C. § 1332.

The statute covers several categories of disputes, including cases between:

• citizens of different states;
• citizens of a state and citizens or subjects of a foreign state, subject to statutory limitations;
• citizens of different states in which foreign citizens or subjects are additional parties, subject to the statute;
• and certain cases involving foreign states or parties under specialized provisions.

The most familiar form is the ordinary case involving citizens of different U.S. states.

For example:

A citizen of California sues a citizen of New York for $150,000 based on a state-law negligence claim.

If the other jurisdictional requirements are satisfied, the case may fall within federal diversity jurisdiction.

The fact that the claim is based on state law does not prevent federal jurisdiction.

That is one of the defining characteristics of diversity jurisdiction.

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Why Does Diversity Jurisdiction Exist?

Diversity jurisdiction has a long history in the federal judicial system.

One traditional justification was concern that a state court might be perceived as biased against an out-of-state litigant.

A nonresident defendant, for example, might fear that local courts or juries would favor a resident plaintiff.

Federal diversity jurisdiction therefore created an alternative forum.

The historical rationale has evolved, and modern federal courts do not assume that state courts are inherently biased.

Nevertheless, diversity jurisdiction remains an important component of the federal judicial system.

It allows qualifying interstate civil disputes to be litigated in federal court even when no federal question is involved.

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Diversity Jurisdiction Is Statutory

An important principle is that diversity jurisdiction does not arise simply because the Constitution permits federal courts to hear a category of cases.

Congress has established the actual jurisdictional rules through federal statutes.

The constitutional grant of federal judicial power is broader than the statutory jurisdiction actually given to federal district courts.

For ordinary diversity cases, 28 U.S.C. § 1332 is therefore essential.

A court must have a constitutional basis for jurisdiction and statutory authorization to exercise it.

This distinction is important throughout federal civil procedure.

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The Two Basic Requirements

The ordinary diversity-jurisdiction analysis has two principal components:

1. Diversity of citizenship, and
2. An amount in controversy exceeding $75,000.

Both requirements generally must be satisfied.

If complete diversity is absent, the case ordinarily does not qualify under § 1332, even if millions of dollars are at stake.

Likewise, if complete diversity exists but the amount in controversy does not exceed $75,000, ordinary diversity jurisdiction is generally unavailable.

The requirements therefore work together.

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Complete Diversity

The traditional rule is known as complete diversity.

Complete diversity generally means that no plaintiff may share state citizenship with any defendant.

For example:

Example 1

Plaintiffs:

• California
• California

Defendants:

• New York
• Texas

Complete diversity exists.

No plaintiff shares citizenship with any defendant.

Example 2

Plaintiffs:

• California
• New York

Defendants:

• Texas
• New York

Complete diversity does not exist.

The New York plaintiff and New York defendant share citizenship.

The presence of even one plaintiff and one defendant sharing citizenship ordinarily defeats complete diversity.

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Complete Diversity Versus Minimal Diversity

Complete diversity should not be confused with minimal diversity.

Minimal diversity generally requires only that at least one plaintiff and one defendant be citizens of different states.

Complete diversity is stricter.

Under the ordinary diversity statute, the federal district court generally requires complete diversity.

However, Congress has created specialized statutory regimes in which minimal diversity can be sufficient.

The Class Action Fairness Act of 2005 (CAFA) is a major example.

Therefore, lawyers should not assume that complete diversity is an absolute requirement for every federal statute invoking diversity concepts.

For ordinary § 1332 diversity jurisdiction, however, complete diversity remains the standard rule.

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Citizenship Is Not the Same as Residence

One of the most important concepts in diversity jurisdiction is that citizenship is not necessarily the same as residence.

A person may live in one state while maintaining citizenship, or domicile, in another.

Section 1332 generally uses citizenship, not simply residence.

Therefore, a complaint that merely states:

“Plaintiff resides in Florida.”

may be insufficient to establish diversity jurisdiction.

The pleading ordinarily needs facts establishing the person’s domicile and citizenship.

Cornell’s citizenship materials explain why citizenship is a distinct jurisdictional concept rather than merely a person’s current residence.

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Domicile and Individual Citizenship

For diversity purposes, an individual’s state citizenship is generally determined by domicile.

Domicile involves both:

1. physical presence in a place, and
2. an intent to remain there indefinitely.

A person can have several residences over time but ordinarily has only one domicile at a particular moment.

For example, imagine that Daniel owns homes in Florida and New York.

He spends several months in each state.

If Florida is his permanent home and he intends to remain there indefinitely, he may be a Florida citizen for diversity purposes even though he spends significant time in New York.

Physical presence is relevant, but domicile requires more than simply being physically present.

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Changing Domicile

A person can change domicile.

Generally, the change requires:

• physical presence in the new state, and
• intent to remain there indefinitely.

Moving to another state temporarily does not necessarily change citizenship.

The issue is therefore determined by the facts surrounding the person’s permanent home and intentions.

Courts may examine objective evidence such as:

• where the person lives,
• where the person works,
• where the person votes,
• where the person pays taxes,
• where the person maintains a driver’s license,
• where the person owns property,
• and other evidence of permanent attachment.

No single factor necessarily controls every case.

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Diversity Is Determined at the Relevant Time

For purposes of an ordinary diversity action, citizenship is generally determined at the time the lawsuit is filed.

This principle is often expressed as the time-of-filing rule.

A later change in citizenship ordinarily does not destroy diversity jurisdiction that properly existed when the case began.

For example, suppose:

• the plaintiff is a New York citizen when the complaint is filed;
• the defendant is a California citizen;
• complete diversity exists;
• the plaintiff later moves to California.

The later move ordinarily does not retroactively eliminate the diversity jurisdiction that existed when the action commenced.

The timing of citizenship therefore matters enormously.

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Citizenship of Corporations

Corporations have a special statutory citizenship rule.

Under 28 U.S.C. § 1332(c)(1), a corporation is generally considered a citizen of:

1. every state and foreign state by which it has been incorporated; and
2. the state or foreign state where it has its principal place of business.

Thus, a corporation can have more than one state of citizenship.

For example:

Corporation X is incorporated in Delaware and has its principal place of business in Texas.

For diversity purposes, Corporation X is generally a citizen of:

• Delaware, and
• Texas.

If a plaintiff is a Texas citizen, complete diversity may therefore be destroyed.

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The Principal Place of Business

The Supreme Court has interpreted a corporation’s principal place of business as its “nerve center” in the ordinary case.

The nerve center is generally the place where the corporation’s officers direct, control, and coordinate the corporation’s activities.

This does not necessarily mean:

• the location with the most employees,
• the largest factory,
• the location generating the most revenue,
• or the state with the greatest volume of business.

The inquiry focuses on the corporation’s principal headquarters and central management.

The Supreme Court’s decision in Hertz Corp. v. Friend is particularly important on this issue.

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Corporations With Extensive Nationwide Operations

A corporation may operate throughout the United States while still having only the statutory citizenship associated with its state or states of incorporation and principal place of business.

For example, a company incorporated in Delaware and headquartered in Illinois may conduct substantial business in:

• California,
• Texas,
• Florida,
• New York,
• Georgia,
• and many other states.

That does not mean the corporation becomes a citizen of every state in which it does business.

This distinction is particularly important in diversity cases involving large corporations.

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Citizenship of LLCs

Limited liability companies are treated differently from corporations.

An LLC generally does not receive the simple two-state citizenship treatment applicable to corporations.

Instead, the citizenship of an LLC is generally determined by the citizenship of all of its members.

This can become complicated because an LLC may have:

• individual members,
• corporate members,
• partnership members,
• other LLC members,
• or members with foreign citizenship.

The court may therefore have to trace the ownership structure through multiple levels.

For example, if an LLC has a corporate member, the citizenship of that corporation must be determined.

If an LLC member is another LLC, the citizenship of the second LLC must also be identified.

This process can continue through the ownership chain.

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Citizenship of Partnerships

Partnerships generally follow a similar principle.

A partnership’s citizenship is generally determined by the citizenship of all of its partners.

This includes situations involving:

• general partnerships,
• limited partnerships,
• and other unincorporated associations.

The citizenship inquiry can therefore be considerably more complicated than the corporate rule.

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Why Entity Citizenship Matters

A lawsuit may appear diverse on the surface but fail the diversity requirement after the parties’ organizational structures are examined.

For example:

Plaintiff: Florida citizen
Defendant: ABC LLC

Simply identifying ABC LLC as an “LLC based in Delaware” does not establish its citizenship.

The court may need to identify every member of the LLC and determine each member’s citizenship.

If one member is a Florida citizen, complete diversity may be destroyed.

This is one of the most common technical problems in diversity pleadings.

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Foreign Citizenship

Section 1332 also covers certain cases involving foreign citizens or subjects.

For example, diversity jurisdiction may exist in a qualifying action between:

• a citizen of a U.S. state, and
• a citizen or subject of a foreign state.

But the statutory rules governing foreign parties contain important limitations and special provisions.

Therefore, cases involving international parties should not be analyzed simply by saying “one party is American and the other is foreign.”

The precise statutory category must be identified.

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Stateless Persons

The diversity statute also addresses certain persons who are not citizens of any state or foreign country.

The jurisdictional treatment of stateless persons is highly technical.

A person who is a U.S. citizen but domiciled abroad may not fit comfortably within the ordinary diversity categories.

For example, the statute contains limitations concerning U.S. citizens domiciled in foreign countries.

Accordingly, international domicile should always be examined carefully rather than assuming that foreign residence automatically creates diversity jurisdiction.

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The Amount-in-Controversy Requirement

The second major requirement for ordinary diversity jurisdiction is the amount in controversy.

Generally, the amount in controversy must exceed $75,000, exclusive of interest and costs.

This means that exactly $75,000 is not enough under the ordinary § 1332 threshold.

The statutory language requires the amount to exceed $75,000.

For example:

• $50,000 → insufficient
• $75,000 → insufficient
• $75,001 → potentially sufficient
• $150,000 → potentially sufficient

Of course, the amount must also be legally placed in controversy and supported under the applicable jurisdictional standards.

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What Counts Toward the Amount in Controversy?

The amount in controversy can include the value of the relief the plaintiff seeks.

Depending on the claim, this may include:

• compensatory damages,
• certain statutory damages,
• punitive damages where legally available,
• and the value of injunctive or declaratory relief.

The relevant question is generally not necessarily what the plaintiff will ultimately recover.

Instead, courts assess the amount that is in controversy under the applicable jurisdictional standards.

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The Amount in Controversy Is Not Necessarily the Final Judgment

A plaintiff may seek $200,000 but ultimately recover only $30,000.

That does not necessarily mean the federal court lacked diversity jurisdiction from the beginning.

Jurisdiction is generally assessed based on the circumstances existing when the action was commenced.

The amount in controversy concerns what was legitimately placed in dispute, not necessarily the amount eventually awarded.

This distinction is crucial.

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The Legal Certainty Standard

When a defendant challenges the amount in controversy, federal courts generally presume that the amount stated by the plaintiff is made in good faith.

Jurisdiction may be defeated if it appears to a legal certainty that the plaintiff cannot recover the required amount.

The precise procedural standards can vary depending on whether the complaint itself establishes the amount or the jurisdictional facts are challenged.

The important point is that a plaintiff does not necessarily have to prove that the plaintiff will actually recover more than $75,000.

The question is whether the amount legally in controversy satisfies the statutory requirement.

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Aggregating Claims

A single plaintiff may generally aggregate multiple claims against a single defendant to satisfy the amount-in-controversy requirement, even if the claims arise from different legal theories, provided the claims are legally permissible.

For example:

• Claim A: $40,000
• Claim B: $40,000

If both claims are properly asserted against the same defendant, the combined amount may exceed $75,000.

However, aggregation rules become more complicated when there are:

• multiple plaintiffs,
• multiple defendants,
• separate legal rights,
• or claims that cannot properly be combined.

The precise rules must therefore be applied to the structure of the lawsuit.

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Multiple Plaintiffs

Multiple plaintiffs cannot always simply add their claims together.

The Supreme Court has recognized circumstances in which multiple plaintiffs may satisfy the amount requirement through supplemental jurisdiction, but the rules depend on the structure of the case.

The key question is whether at least one plaintiff independently satisfies the amount-in-controversy requirement and whether the remaining claims fall within the court’s supplemental jurisdiction under 28 U.S.C. § 1367.

The relationship between diversity jurisdiction and supplemental jurisdiction is therefore particularly important in multi-party litigation.

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Multiple Defendants

Similarly, a plaintiff generally cannot automatically aggregate unrelated claims against separate defendants merely to exceed $75,000.

For example:

• $40,000 claim against Defendant A
• $40,000 unrelated claim against Defendant B

does not automatically become an $80,000 controversy simply because both defendants are named in the same lawsuit.

The claims and parties must be analyzed under the applicable aggregation and supplemental-jurisdiction principles.

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Injunctive Relief and the Amount in Controversy

Some lawsuits seek an injunction rather than a specific amount of money.

In those cases, courts may evaluate the value of the object of the litigation or the value of the right that the plaintiff seeks to protect.

The valuation question can become complex.

For example, a plaintiff might seek an injunction preventing a defendant from engaging in conduct that allegedly threatens a business interest worth hundreds of thousands of dollars.

The court may need to determine the relevant value for jurisdictional purposes.

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Declaratory Judgments

Declaratory actions can also satisfy the amount-in-controversy requirement.

The court may examine the value of the legal rights or obligations that the declaration would affect.

For example, if the plaintiff seeks a declaration concerning ownership of property or contractual rights worth more than $75,000, the value of the underlying dispute may potentially satisfy the jurisdictional requirement.

The exact analysis depends on the nature of the controversy.

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Punitive Damages

Punitive damages can sometimes contribute to the amount in controversy when they are legally available.

But a plaintiff cannot simply demand an enormous punitive-damages figure without a legal basis.

Courts may examine whether punitive damages are available under the applicable substantive law and whether the claimed amount is legally supportable.

Thus, the amount in controversy is based on the legitimate legal dispute, not an artificially inflated number.

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Attorney’s Fees

Attorney’s fees generally are not automatically included in the amount in controversy.

However, if applicable substantive law or a contractual provision makes attorney’s fees recoverable by the prevailing party, those fees may sometimes be considered.

The precise treatment depends on the governing law.

The distinction is therefore between fees that are merely expected litigation expenses and fees that are legally recoverable as part of the substantive relief.

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Costs and Interest

Section 1332 expressly refers to the amount in controversy exclusive of interest and costs.

This means ordinary interest and litigation costs generally do not count toward the $75,000 threshold.

This is another reason why a claim for $75,000 plus interest and court costs does not ordinarily satisfy the statutory threshold.

The statutory language must be applied precisely.

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Diversity Jurisdiction and State Law Claims

A diversity case commonly involves state-law claims.

For example, a plaintiff may sue for:

• negligence,
• breach of contract,
• fraud,
• defamation,
• property damage,
• or another state-law cause of action.

If the parties are completely diverse and the amount in controversy exceeds $75,000, the federal court may hear the case.

The federal court does not transform the state-law claim into a federal claim merely because it is sitting in federal court.

Instead, the court exercises federal jurisdiction over a state-law dispute.

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Erie and Diversity Jurisdiction

One of the most important consequences of diversity jurisdiction is the application of the Erie doctrine.

When a federal court hears a state-law claim under diversity jurisdiction, the court generally applies:

• federal procedural law where applicable, and
• state substantive law under the Erie framework.

The classic principle comes from Erie Railroad Co. v. Tompkins.

For example, a federal court hearing a diversity negligence case may apply:

• the Federal Rules of Civil Procedure to procedural matters,
• while applying the relevant state’s substantive negligence law.

This distinction is central to federal civil litigation.

Cornell’s overview of Erie doctrine provides a useful introduction to the principle governing state substantive law in federal diversity cases.

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Federal Rules in Diversity Cases

The fact that state substantive law applies does not mean that state procedural rules automatically govern the federal case.

Federal courts ordinarily apply the Federal Rules of Civil Procedure where those rules validly govern procedure.

The interaction between federal procedural rules and state law can sometimes produce difficult Erie and Hanna v. Plumer questions.

Thus, diversity jurisdiction creates a distinctive procedural environment:

A federal court may decide a state-law dispute while applying federal procedural rules.

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Supplemental Jurisdiction and Diversity Cases

A diversity case may contain additional claims or parties that do not independently satisfy § 1332.

28 U.S.C. § 1367 may allow federal courts to exercise supplemental jurisdiction over additional claims that form part of the same constitutional case or controversy.

However, diversity cases receive special treatment.

Section 1367(b) restricts certain supplemental claims in actions founded solely on diversity jurisdiction.

These limitations are designed to preserve the basic requirements Congress established for diversity jurisdiction.

Cornell’s supplemental jurisdiction materials explain the relationship between § 1332 and § 1367 and the special limitations applicable to diversity cases.

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Diversity and Counterclaims

Counterclaims can create complicated jurisdictional issues.

Some counterclaims may fall within the court’s original jurisdiction.

Others may depend on supplemental jurisdiction.

The analysis may turn on:

• whether the counterclaim is compulsory or permissive,
• whether it arises from the same transaction or occurrence,
• whether it independently satisfies diversity jurisdiction,
• and whether § 1367 permits supplemental jurisdiction.

A diversity case therefore does not automatically provide federal jurisdiction over every claim asserted by every party.

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Diversity and Crossclaims

Crossclaims between co-parties can also raise supplemental-jurisdiction questions.

A crossclaim may be part of the same constitutional case or controversy as the original dispute even though it does not independently satisfy diversity jurisdiction.

Section 1367 may therefore become important.

The fact that the original case entered federal court through diversity jurisdiction does not mean every subsequent claim automatically falls within the court’s authority.

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Diversity and Third-Party Claims

Third-party practice creates another layer of complexity.

A defendant may bring a third-party claim against another person who may be responsible for all or part of the plaintiff’s claim.

That third-party claim may not independently satisfy diversity jurisdiction.

Nevertheless, supplemental jurisdiction may sometimes permit it.

The rules must be analyzed carefully, especially where the plaintiff later seeks to assert claims directly against the third-party defendant.

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Real Party in Interest

Diversity jurisdiction generally focuses on the citizenship of the real parties in interest.

This prevents parties from manipulating jurisdiction simply by placing a nominal or formal party into the litigation.

The court may need to determine who actually possesses the legal right being enforced.

This issue becomes particularly important in cases involving:

• trustees,
• executors,
• administrators,
• representatives,
• guardians,
• and other fiduciary or representative relationships.

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Representatives of Estates

The citizenship of a personal representative does not necessarily determine the citizenship of the estate for diversity purposes.

Federal law contains special rules governing certain representatives.

Under 28 U.S.C. § 1332(c)(2), the legal representative of the estate of a decedent is deemed to be a citizen of the same state as the decedent.

Special rules also apply to representatives of minors and incompetent persons.

These provisions prevent jurisdiction from turning entirely on the representative’s personal citizenship.

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Class Actions and Diversity

Class actions have special jurisdictional rules.

The Class Action Fairness Act (CAFA) significantly expanded federal jurisdiction over certain class actions.

CAFA generally allows federal jurisdiction where:

• the aggregate amount in controversy exceeds $5 million,
• there is minimal diversity,
• and other statutory requirements are satisfied.

The requirements and exceptions are detailed and should not be confused with ordinary § 1332 diversity jurisdiction.

CAFA therefore represents an important statutory departure from the traditional complete-diversity model.

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Removal Based on Diversity

Diversity jurisdiction also plays an important role in removal.

A defendant sued in state court may, where the statutory requirements are satisfied, remove the case to federal court.

The defendant must establish a proper basis for federal subject-matter jurisdiction.

Diversity removal is subject to additional rules.

One particularly important principle is the forum-defendant rule under 28 U.S.C. § 1441(b)(2).

Generally, a diversity action otherwise removable solely on diversity grounds may not be removed if any of the properly joined and served defendants is a citizen of the forum state.

This rule is statutory rather than a constitutional limitation.

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The Forum-Defendant Rule

The forum-defendant rule reflects the historical rationale of diversity jurisdiction.

If diversity jurisdiction is designed in part to protect out-of-state defendants from perceived local bias, the justification is weaker when the defendant is itself a citizen of the forum state.

Thus, even when complete diversity and the amount-in-controversy requirement exist, a forum defendant may prevent removal under the rule.

The rule should be distinguished from the constitutional requirement of complete diversity.

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The One-Year Limitation on Diversity Removal

In ordinary diversity cases removed from state court, 28 U.S.C. § 1446(c)(1) generally imposes a one-year limitation on removal after commencement of the action, subject to statutory exceptions.

This is another example of why diversity jurisdiction and removal jurisdiction must be analyzed separately.

A case may qualify substantively for diversity jurisdiction while still encountering a procedural obstacle to removal.

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Fraudulent Joinder

A plaintiff may sometimes attempt to prevent removal by naming a nondiverse defendant.

Federal courts recognize the doctrine of fraudulent joinder, under which a plaintiff’s improper inclusion of a nondiverse defendant may be disregarded for diversity purposes when the applicable legal standard is satisfied.

The doctrine is narrowly applied.

A defendant generally cannot simply label a co-defendant “fraudulently joined” because the plaintiff’s claim against that defendant is weak.

The question concerns whether there is a legally reasonable basis for the claim or whether the nondiverse party was improperly joined to defeat federal jurisdiction.

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Diversity Jurisdiction Cannot Be Created by Agreement

Parties generally cannot create federal subject-matter jurisdiction simply by agreeing that a federal court should hear their dispute.

If complete diversity or the amount-in-controversy requirement is absent, the parties cannot manufacture jurisdiction through consent.

This is another important difference between subject-matter jurisdiction and personal jurisdiction.

Personal jurisdiction can generally be consented to.

Subject-matter jurisdiction cannot ordinarily be created by party agreement.

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Diversity Jurisdiction and Waiver

Subject-matter jurisdiction is fundamentally different from personal jurisdiction in this respect.

A defendant may waive a personal-jurisdiction objection.

But a lack of subject-matter jurisdiction generally cannot be cured by waiver or consent.

A federal court must have actual jurisdiction.

If the court discovers that diversity jurisdiction is absent, it must address the problem even if the parties did not raise it.

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Rule 12(b)(1)

A party may challenge federal subject-matter jurisdiction under Federal Rule of Civil Procedure 12(b)(1).

A diversity-jurisdiction challenge might argue that:

• the parties are not completely diverse,
• the amount in controversy is insufficient,
• a party’s citizenship has been incorrectly alleged,
• an entity’s citizenship was improperly determined,
• or another statutory limitation applies.

The court may examine the jurisdictional allegations and, when necessary, jurisdictional facts.

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Pleading Citizenship Correctly

Diversity complaints must identify citizenship with sufficient precision.

For an individual, stating:

“Plaintiff resides in California”

may not be enough.

A better jurisdictional allegation generally identifies the person’s domicile.

For a corporation, the complaint should ordinarily identify:

• the state or states of incorporation, and
• the principal place of business.

For an LLC or partnership, the citizenship of all relevant members or partners may need to be established.

Jurisdictional pleading should therefore be treated as a substantive procedural task rather than a formality.

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Citizenship of an LLC: A Practical Example

Suppose:

• Plaintiff is a citizen of New York.
• Defendant is an LLC organized under Delaware law.
• The LLC has two members.
• Member 1 is a citizen of Florida.
• Member 2 is an LLC whose members are citizens of Texas and New Jersey.

The defendant LLC’s citizenship potentially includes:

• Florida,
• Texas,
• and New Jersey.

The fact that the LLC was formed under Delaware law does not automatically make it a Delaware citizen for diversity purposes.

This is a crucial distinction between corporations and unincorporated entities.

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What If a Party Changes Citizenship?

Suppose a diversity case is properly filed while:

• Plaintiff is a citizen of Ohio,
• Defendant is a citizen of Michigan.

The plaintiff later moves to Michigan.

The later move ordinarily does not destroy the diversity jurisdiction that existed when the case commenced.

This illustrates the importance of the time-of-filing rule.

However, procedural events such as amendments, substitution of parties, or other changes can create complicated jurisdictional questions.

The exact procedural posture matters.

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Diversity Jurisdiction and Settlement

Settlement does not create a jurisdictional problem merely because the eventual recovery is less than $75,000.

The jurisdictional inquiry concerns the amount in controversy at the relevant time, not simply the final settlement amount.

Thus, a case properly within diversity jurisdiction may be resolved for:

• $20,000,
• $50,000,
• $75,000,

or another amount below the original jurisdictional threshold.

The settlement does not ordinarily retroactively eliminate jurisdiction.

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Diversity Jurisdiction and Damages That Are Uncertain

Many lawsuits involve uncertain damages.

A plaintiff may suffer significant injuries but be unable to determine the precise monetary value of the claim at the beginning of litigation.

Federal courts do not necessarily require mathematical certainty at the jurisdictional stage.

The question is whether the amount in controversy legally exceeds $75,000 under the applicable standard.

Evidence may become relevant when the defendant contests the jurisdictional amount.

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Diversity Jurisdiction and State Procedural Rules

Once a diversity case is properly in federal court, the federal court generally follows federal procedural law rather than simply applying the forum state’s civil procedure rules.

For example, the Federal Rules of Civil Procedure govern matters such as:

• pleading,
• discovery,
• motions,
• joinder,
• summary judgment,
• and trial procedure,

when applicable.

State law remains critically important for substantive issues.

This division is one of the defining characteristics of diversity litigation.

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Diversity Jurisdiction and Federalism

Diversity jurisdiction sits at the intersection of federal and state judicial authority.

The underlying dispute may arise entirely under state law.

Yet Congress has authorized federal courts to hear certain interstate disputes.

The federal court therefore acts as a federal tribunal resolving a dispute that may be governed substantially by state substantive law.

This arrangement reflects the dual sovereignty of the American legal system.

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Common Mistakes in Diversity Jurisdiction

Mistake 1: “Different residences mean diversity.”

Not necessarily.

Citizenship generally depends on domicile, not simply residence.

Mistake 2: “An LLC is a citizen where it was formed.”

Generally incorrect.

An LLC’s citizenship is ordinarily determined through its members.

Mistake 3: “A corporation is a citizen only where it is incorporated.”

Incorrect.

A corporation is generally a citizen of both its state or states of incorporation and its principal place of business.

Mistake 4: “$75,000 is enough.”

Not under the ordinary § 1332 amount requirement.

The amount must generally exceed $75,000, exclusive of interest and costs.

Mistake 5: “All plaintiffs can combine their damages.”

Not automatically.

Aggregation depends on the nature of the claims and the applicable jurisdictional rules.

Mistake 6: “A federal court automatically has jurisdiction because the parties are from different states.”

No.

The amount-in-controversy requirement and other statutory requirements must also be satisfied.

Mistake 7: “The parties can agree to federal diversity jurisdiction.”

Not if statutory subject-matter jurisdiction is absent.

Mistake 8: “A later move to another state destroys diversity.”

Generally, not when diversity existed at the time the action was commenced.

Mistake 9: “State law does not matter in a diversity case.”

Incorrect.

State substantive law can be central under the Erie doctrine.

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A Practical Diversity-Jurisdiction Checklist

When analyzing diversity jurisdiction, ask the following questions.

1. What statute provides jurisdiction?

Usually, ordinary diversity jurisdiction is based on 28 U.S.C. § 1332.

2. Who are the parties?

Identify every plaintiff and every defendant.

3. What is each party’s citizenship?

Do not rely merely on residence.

4. Are the individuals domiciled in different states?

Determine each person’s domicile.

5. Are any parties corporations?

Identify:

• incorporation,
• principal place of business.

6. Are any parties unincorporated entities?

Trace the citizenship of:

• LLC members,
• partners,
• and other relevant owners.

7. Is complete diversity present?

No plaintiff should ordinarily share citizenship with any defendant under the ordinary § 1332 framework.

8. Does the amount in controversy exceed $75,000?

Remember that the threshold is more than $75,000, excluding interest and costs.

9. Can claims be aggregated?

Analyze the claims and parties individually.

10. Does supplemental jurisdiction matter?

Consider § 1367 for additional claims or parties.

11. Is the case being removed?

If so, examine the removal statutes and the forum-defendant rule.

12. Is the case a class action?

If so, determine whether CAFA or another specialized jurisdictional statute applies.

13. Does Erie apply?

If the federal court is exercising diversity jurisdiction over state-law claims, identify the applicable state substantive law and federal procedural law.

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A Complete Example

Consider the following hypothetical.

Anna is domiciled in Illinois.

She sues XYZ Corporation in federal court.

XYZ Corporation:

• is incorporated in Delaware,
• has its principal place of business in Texas.

Anna claims $250,000 in damages for negligence under Illinois law.

Step One: Citizenship

Anna is a citizen of Illinois.

XYZ is a citizen of:

• Delaware, and
• Texas.

No plaintiff and defendant share citizenship.

Complete diversity exists.

Step Two: Amount in Controversy

Anna seeks $250,000.

The amount exceeds $75,000.

The amount requirement is satisfied, assuming the claim is legally capable of supporting that amount.

Step Three: Nature of the Claim

The claim arises under Illinois tort law rather than federal law.

That does not matter.

Diversity jurisdiction can support federal jurisdiction over qualifying state-law claims.

Step Four: Applicable Law

Because the federal court is hearing the case under diversity jurisdiction, the court must apply the appropriate Erie framework to determine which state substantive law governs while using applicable federal procedural law.

The case therefore illustrates the basic operation of diversity jurisdiction.

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A More Complicated Example: LLC Defendant

Now suppose Anna sues ABC LLC.

ABC LLC is organized in Delaware and headquartered in Texas.

Anna assumes ABC LLC is therefore a Delaware or Texas citizen.

That assumption may be wrong.

The court must generally identify every member of ABC LLC.

Suppose:

• Member 1 is a citizen of California.
• Member 2 is an LLC.
• Member 2 has members who are citizens of Florida and Illinois.

ABC LLC may therefore be considered a citizen of:

• California,
• Florida,
• and Illinois.

Because Anna is an Illinois citizen, complete diversity would be absent.

The federal court would ordinarily lack diversity jurisdiction under § 1332.

This example demonstrates why determining the citizenship of unincorporated entities can be one of the most demanding aspects of diversity jurisdiction.

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Diversity Jurisdiction and the Limits of Federal Judicial Power

Diversity jurisdiction demonstrates that federal courts do not exercise jurisdiction simply because a dispute crosses state lines.

Congress has established detailed conditions.

The court must determine:

• whether the parties have the required citizenship,
• whether the amount in controversy exceeds the statutory threshold,
• whether special statutory restrictions apply,
• and whether any additional claims fall within original or supplemental jurisdiction.

These requirements preserve the limited jurisdiction of federal courts.

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Diversity Jurisdiction and the Role of the Federal Courts

Diversity jurisdiction gives federal courts an important role in interstate civil litigation.

It allows qualifying disputes to be heard in federal court even when the substantive law is entirely state law.

At the same time, the restrictions built into § 1332 prevent diversity jurisdiction from becoming a general federal forum for every state-law dispute.

The doctrine therefore reflects a balance.

Federal courts provide a national judicial forum for qualifying interstate controversies, while state courts retain primary responsibility for the enormous body of disputes that do not fall within federal jurisdiction.

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Key Takeaways

Diversity jurisdiction is one of the principal bases of federal subject-matter jurisdiction.

The most important points are:

1. The principal statute is 28 U.S.C. § 1332.
2. Ordinary diversity jurisdiction generally requires complete diversity of citizenship.
3. No plaintiff may ordinarily share citizenship with any defendant.
4. Individual citizenship is generally based on domicile, not merely residence.
5. A corporation is generally a citizen of its state or states of incorporation and its principal place of business.
6. An LLC generally has the citizenship of all of its members.
7. Partnership citizenship generally follows the citizenship of all partners.
8. The amount in controversy must ordinarily exceed $75,000, exclusive of interest and costs.
9. Claims may sometimes be aggregated, but the rules depend on the parties and claims involved.
10. Diversity is generally assessed at the time the action is commenced.
11. A later change in citizenship ordinarily does not destroy properly established diversity jurisdiction.
12. Supplemental jurisdiction can sometimes support additional claims in a diversity action, subject to § 1367’s limitations.
13. CAFA provides specialized diversity-based jurisdiction for qualifying class actions.
14. Diversity removal is subject to additional statutory rules, including the forum-defendant rule.
15. A federal court exercising diversity jurisdiction generally applies the Erie framework to determine the governing substantive law.
16. Parties cannot create subject-matter jurisdiction merely by agreeing to federal jurisdiction.
17. Diversity jurisdiction is a form of subject-matter jurisdiction and therefore cannot ordinarily be waived.

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Frequently Asked Questions

What is diversity jurisdiction?

Diversity jurisdiction allows federal courts to hear certain civil disputes involving citizens of different states or qualifying disputes involving foreign citizens, when the statutory requirements are satisfied.

What are the requirements for diversity jurisdiction?

Ordinary diversity jurisdiction generally requires:

• complete diversity of citizenship, and
• an amount in controversy exceeding $75,000, exclusive of interest and costs.

Other statutory requirements may apply depending on the parties and type of case.

What does complete diversity mean?

Complete diversity generally means that no plaintiff shares state citizenship with any defendant.

Is residence the same as citizenship?

No.

For individuals, diversity citizenship is generally based on domicile rather than simply residence.

How is an individual’s domicile determined?

Domicile generally requires physical presence in a state together with an intent to remain there indefinitely.

How is a corporation’s citizenship determined?

A corporation is generally a citizen of every state or foreign state where it is incorporated and the state or foreign state where it has its principal place of business.

How is an LLC’s citizenship determined?

An LLC generally has the citizenship of all of its members.

How much money must be in controversy?

For ordinary diversity jurisdiction under § 1332, the amount in controversy must generally exceed $75,000, exclusive of interest and costs.

Does the plaintiff have to actually recover more than $75,000?

No.

The amount in controversy concerns the value legitimately placed in dispute when the case is commenced, not necessarily the amount ultimately recovered.

Can multiple claims be combined to reach $75,000?

A single plaintiff may generally aggregate certain claims against a single defendant. The rules become more complicated with multiple plaintiffs or defendants.

Can parties consent to diversity jurisdiction?

No.

Subject-matter jurisdiction cannot ordinarily be created simply through party agreement.

Can diversity jurisdiction be waived?

Subject-matter jurisdiction generally cannot be waived in the same way as personal jurisdiction.

What happens if the parties are not completely diverse?

Unless another federal jurisdictional basis applies, the federal court generally lacks diversity jurisdiction.

Does an LLC’s state of formation determine its citizenship?

Generally, no.

Unlike a corporation, an LLC’s citizenship is ordinarily based on the citizenship of its members.

What is the Erie doctrine?

The Erie doctrine governs the relationship between state substantive law and federal procedural law when a federal court hears state-law claims, particularly in diversity cases.

Can a diversity case be removed from state court?

Yes, when the statutory requirements for removal are satisfied. Diversity removal has additional restrictions, including the forum-defendant rule.

Does diversity jurisdiction apply to class actions?

Yes, but class actions may be governed by specialized rules, particularly the Class Action Fairness Act, which permits federal jurisdiction under conditions different from ordinary § 1332 cases.

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Conclusion

Diversity jurisdiction is a foundational part of federal civil procedure because it allows federal courts to hear certain disputes that do not arise under federal law.

Its central requirements are straightforward in theory but technically demanding in practice: the parties must generally be completely diverse, and the amount in controversy must exceed $75,000, exclusive of interest and costs.

The difficult part is often determining what those requirements actually mean.

Citizenship is not simply residence. Individual citizenship generally depends on domicile. Corporations have citizenship based on incorporation and principal place of business. LLCs and partnerships require examination of their members or partners. The amount in controversy concerns the value legally placed in dispute rather than necessarily the eventual judgment. Additional claims and parties may implicate supplemental jurisdiction, while class actions and removal proceedings can trigger specialized statutory rules.

Diversity jurisdiction also illustrates the distinctive role of federal courts in the American legal system. A federal court may hear a dispute governed almost entirely by state substantive law while applying federal procedural rules. Through the Erie doctrine, the federal court respects the substantive law of the states while functioning as a federal judicial forum.

Ultimately, diversity jurisdiction is not simply about whether two parties come from different states. It is a carefully structured jurisdictional system designed to determine when an interstate civil controversy belongs in federal court.

Understanding citizenship, domicile, complete diversity, the amount in controversy, entity citizenship, supplemental jurisdiction, removal, and the Erie doctrine provides the foundation for understanding how diversity cases actually move through the federal courts.

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