Diversity Jurisdiction Guide
Diversity jurisdiction under 28 U.S.C. Section 1332 gives federal courts the power to hear civil disputes between citizens of different states when the amount in controversy exceeds $75,000, exclusive of interest and costs. The constitutional basis for diversity jurisdiction is Article III, Section 2, which extends the judicial power to controversies "between Citizens of different States." Congress has implemented this authority through Section 1332, imposing the additional requirement of complete diversity and a monetary threshold. The traditional justification for diversity jurisdiction is the protection of out-of-state litigants from potential local bias in state courts.
Complete diversity, established by Strawbridge v. Curtiss (1806), requires that no plaintiff share state citizenship with any defendant. This is a stricter requirement than Article III's allowance of minimal diversity (at least one diverse pair), and Congress has chosen to require complete diversity for general diversity jurisdiction. Citizenship for individuals is determined by domicile — the state where a person resides with the intent to remain indefinitely. For corporations, Section 1332(c)(1) provides dual citizenship: the state of incorporation and the state where the corporation has its principal place of business (the "nerve center" under Hertz Corp. v. Friend). For unincorporated entities such as LLCs, partnerships, and unions, citizenship is determined by the citizenship of every member.
The amount-in-controversy requirement serves as a gatekeeping mechanism to ensure that only substantial disputes occupy federal court resources. A plaintiff's good-faith allegation of damages exceeding $75,000 is generally accepted unless it appears to a legal certainty that the claim is really for less. A single plaintiff may aggregate all claims against a single defendant to meet the threshold, but generally, multiple plaintiffs cannot aggregate their separate and distinct claims. Under Exxon Mobil Corp. v. Allapattah Services (2005), supplemental jurisdiction permits additional plaintiffs who do not independently meet the amount threshold to join the case if at least one plaintiff satisfies it.
Diversity jurisdiction is one of the most heavily tested topics on civil procedure exams because it involves technical rules about citizenship determination, timing, corporate structure, amount calculation, and aggregation that reward careful, methodical analysis. Professors frequently design exam questions featuring LLCs with members in multiple states, class actions with varying amounts, or parties who have recently relocated, all of which test whether students can correctly determine citizenship and apply the complete diversity rule.
Key Elements
- 1
Complete Diversity
Every plaintiff must be diverse from every defendant. If any plaintiff shares citizenship with any defendant, complete diversity is destroyed and diversity jurisdiction does not exist under Section 1332(a).
- 2
Citizenship of Individuals (Domicile)
An individual is a citizen of the state where they are domiciled — physical presence plus intent to remain indefinitely. Domicile is determined at the time the complaint is filed and does not change with temporary relocations.
- 3
Citizenship of Corporations
A corporation is a citizen of (1) every state where it is incorporated and (2) the one state where it has its principal place of business (the 'nerve center' — typically the headquarters where officers direct and control corporate activities).
- 4
Citizenship of Unincorporated Entities
LLCs, partnerships, limited partnerships, and other unincorporated associations take the citizenship of every one of their members, which can destroy diversity if any member shares citizenship with an opposing party.
- 5
Amount in Controversy
The amount in controversy must exceed $75,000, exclusive of interest and costs. The plaintiff's good-faith allegation controls unless the defendant demonstrates to a legal certainty that the amount cannot be met.
- 6
Timing of Diversity
Diversity of citizenship and the amount in controversy are both measured at the time the complaint is filed. Subsequent changes in citizenship or claim value do not destroy jurisdiction.
Step-by-Step Analysis Flowchart
- Step 1: Identify every plaintiff and every defendant in the case.
- Step 2: Determine the citizenship of each individual party based on domicile (physical presence + intent to remain indefinitely) at the time the complaint was filed.
- Step 3: Determine the citizenship of each corporate party: state(s) of incorporation and the one state where the nerve center (principal place of business) is located.
- Step 4: Determine the citizenship of any unincorporated entities by identifying the citizenship of every member (and, for multi-tiered entities, trace through to the ultimate individual or corporate members).
- Step 5: Check for complete diversity: Confirm that no plaintiff shares state citizenship with any defendant.
- Step 6: Assess the amount in controversy: Does the plaintiff's good-faith claim exceed $75,000?
- Step 7: If a single plaintiff has multiple claims against a single defendant, aggregate all claims (regardless of whether they are related).
- Step 8: If multiple plaintiffs each have claims, determine whether any plaintiff independently meets the $75,000 threshold — if so, supplemental jurisdiction under Section 1367 may apply to the others (Allapattah).
- Step 9: Consider whether any statutory exceptions (e.g., domestic relations, probate) preclude federal jurisdiction.
- Step 10: Confirm that diversity jurisdiction exists under Section 1332(a) and that no jurisdictional defect requires dismissal.
Key Rules
- Complete diversity requires that no plaintiff share citizenship with any defendant — even one overlapping citizenship pair destroys diversity (Strawbridge v. Curtiss).
- An individual's citizenship is their domicile: the last state where they were physically present with the intent to remain indefinitely (Mas v. Perry).
- A corporation has dual citizenship — its state of incorporation and its principal place of business ('nerve center') (Hertz Corp. v. Friend).
- Unincorporated entities (LLCs, partnerships) take the citizenship of all members — there is no 'state of organization' citizenship for these entities.
- The amount in controversy is judged from the plaintiff's perspective at the time of filing, using the legal certainty test (St. Paul Mercury Indemnity Co.).
- A single plaintiff may aggregate all claims against a single defendant, but multiple plaintiffs cannot aggregate their separate claims to meet the threshold.
Common Exam Patterns
An LLC is a defendant — students must trace through to identify every member's citizenship, not just the state of organization.
A plaintiff recently relocated to a new state and filed suit — tests whether domicile (intent to remain) was established before filing.
A plaintiff seeks injunctive relief rather than money damages — tests how to value equitable relief for the amount-in-controversy requirement.
A corporation is incorporated in Delaware but headquartered in New York — tests dual corporate citizenship and which state controls.
Multiple plaintiffs join suit with varying claim amounts, some above and some below $75,000 — tests Allapattah and supplemental jurisdiction.
Defendant argues the actual damages are well below $75,000 — tests the legal certainty standard and who bears the burden of proof.
Landmark Cases
Strawbridge v. Curtiss (1806)
Established the complete diversity rule for Section 1332: every plaintiff must be diverse from every defendant, which is more restrictive than Article III's minimal diversity requirement.
Mas v. Perry (1974)
Clarified that domicile, not residence, determines citizenship for diversity purposes. A student living in Louisiana for school but intending to return to Mississippi remained a Mississippi citizen.
Hertz Corp. v. Friend (2010)
Adopted the 'nerve center' test for corporate principal place of business — it is the single location where a corporation's officers direct, control, and coordinate its activities, typically the headquarters.
Exxon Mobil Corp. v. Allapattah Services, Inc. (2005)
Held that in a diversity case, supplemental jurisdiction under Section 1367 allows additional plaintiffs who do not meet the amount-in-controversy requirement to join if at least one plaintiff does.
St. Paul Mercury Indemnity Co. v. Red Cab Co. (1938)
Established the legal certainty test for the amount in controversy: the plaintiff's good-faith claim controls unless it appears to a legal certainty that the amount cannot be met.
Tips for Success
- Always trace LLC and partnership membership all the way down to natural persons or corporations — multi-tiered entities can hide citizenship-destroying members several layers deep.
- Remember that domicile requires both physical presence and intent to remain indefinitely. Students living in a state temporarily for school are generally domiciled in their home state.
- For the amount in controversy, think creatively: the plaintiff can include compensatory damages, punitive damages, attorney's fees (if authorized by statute or contract), and the value of injunctive relief.
- Corporate citizenship always includes both the state of incorporation AND the principal place of business — do not forget to check both when determining if diversity is destroyed.
- Timing is everything: diversity and the amount in controversy are measured at the time of filing. Post-filing changes (a party moves, claim value drops) are irrelevant.
- Class actions have special rules under CAFA (28 U.S.C. Section 1332(d)) — minimal diversity suffices, and the aggregate amount must exceed $5 million. Do not confuse CAFA with standard diversity.
- When in doubt about the amount in controversy, note that the burden is on the party challenging jurisdiction to prove to a legal certainty that the threshold is not met.