The General Statutory Grant

Section 1367(a) is the statute's general grant of supplemental jurisdiction. In any civil action of which the district courts have original jurisdiction, the courts have supplemental jurisdiction over all other claims so related to the claims within that original jurisdiction that they form part of the same case or controversy under Article III, and the grant extends to claims that involve the joinder or intervention of additional parties.¹ The previous section told the history behind that sentence. This section reads it closely and splits it into the three questions a student asks of every fact pattern.

The grant is broad by design. Congress used it to give the federal courts a larger share of Article III jurisdiction than the standard jurisdictional statutes provide, so that a case holding at least one claim with a federal basis can carry its related claims along and achieve efficiencies.² Two features of the text keep that breadth in check. The grant works only inside a civil action in which the court already has original jurisdiction, so every claim that travels must travel with a claim holding its own ticket. And it measures relatedness by the Article III standard, so the statute reaches as far as the constitutional case that Gibbs defined and stops there.³

The grant also opens with a qualification that governs everything below. It applies “except as provided in subsections (b) and (c) or as expressly provided otherwise by Federal statute,” so subsection (a) states a default rule and not a final answer.⁴ Subsection (b) withholds supplemental jurisdiction over certain claims by plaintiffs in actions founded solely on diversity, when exercising it would be inconsistent with § 1332.⁵ Subsection (c) lets a court decline jurisdiction that subsection (a) would otherwise give it, as when the claim raises a novel or complex issue of state law, substantially predominates over the claims within original jurisdiction, or remains after the court has dismissed every claim over which it had original jurisdiction.⁶ A claim that satisfies subsection (a) is therefore only provisionally within the court's power, and later sections take up each limit in turn.

The three subsections below follow the order of the words in the grant, and each poses a question that a claim must answer favorably. The opening phrase requires a civil action of which the district courts have original jurisdiction, so the analysis starts by finding the anchor claim. The next phrase sets the standard of relatedness between that anchor and the added claim. The closing sentence addresses additional parties.

The Anchor Claim Requirement

Supplemental jurisdiction exists only “in any civil action of which the district courts have original jurisdiction,” and it then reaches only “all other claims” so related to claims within that original jurisdiction that they form part of the same case or controversy.⁷ The claim that supplies the original jurisdiction is the anchor claim. It holds jurisdiction on its own under § 1331, § 1332, or some other jurisdictional statute, with no help from any other claim. Supplemental jurisdiction therefore never operates by itself. It supplements jurisdiction already taken elsewhere, so a court cannot conclude that a claim takes supplemental jurisdiction until it has first found a prior claim that qualifies independently.⁸

The text shows why this step cannot be skipped. The statute measures a claim's relationship to “claims in the action within such original jurisdiction,” so the relatedness inquiry has a reference point only when an anchor exists.⁹ A court cannot ask whether a claim forms part of the same case as an anchor that does not exist. The consequence is blunt: if no claim stands on its own, the court has nothing to supplement, and the entire action is dismissed for lack of subject-matter jurisdiction, however closely the claims are connected.¹⁰ Students often offer a close connection between the claims as a substitute for the missing anchor, and it is never an adequate one.

Any independent basis can serve as the anchor. A federal-question claim under § 1331 qualifies, as does a diversity claim that meets the citizenship and amount requirements of § 1332, and so does a claim within another jurisdictional statute, such as the exclusive federal jurisdiction over patent cases under 28 U.S.C. § 1338.¹¹ Losing an anchor after the case is underway is a different problem. Section 1367(c)(3) lets a court decline supplemental jurisdiction once it has dismissed every claim over which it had original jurisdiction, and a later section takes up that discretion.¹²

The sequence of those questions comes from Exxon Mobil Corp. v. Allapattah Services, Inc. Once the court determines that it has original jurisdiction over the civil action, the Court explained, it can turn to whether it has a constitutional and statutory basis for exercising supplemental jurisdiction over the other claims in the action.¹³ The order is anchor first and relatedness second. That order explains why Coleridge's shortfall does not end the case: once one plaintiff's claim qualifies, supplemental jurisdiction relieves the other plaintiffs of having to satisfy the amount in controversy themselves.¹⁴ Later sections return to Allapattah in detail.

Every plaintiff must separately satisfy the amount-in-controversy requirement, and the Court has long held that the suit should be dismissed as to any plaintiff who fails to show the requisite amount.¹⁵ Plaintiffs may not aggregate their claims to reach the amount unless they share a single title or right, so Fenn's and Gale's combined $100,000 accomplishes nothing.¹⁶ Because no claim stands on its own, § 1367(a) has nothing to supplement.¹⁷ Fenn and Gale differ from Browning and Coleridge in one respect only: whether some single claim clears $75,000. The closeness of the connection between the claims is the same in both pairs, and it cannot stand in for the missing anchor.

Diversity supplies a second way to lose the anchor, and it works differently from the amount requirement. Complete diversity cannot be analyzed claim by claim. When a single plaintiff shares a state's citizenship with a single defendant, diversity is incomplete, and incomplete diversity destroys original jurisdiction with respect to all claims, leaving nothing to which supplemental jurisdiction can adhere.¹⁸ The federal-question and amount-in-controversy requirements, by contrast, can be analyzed claim by claim, so a shortfall in one claim's amount leaves a qualifying claim untouched.¹⁹

The two defects must be sorted by type. A claim that misses the jurisdictional amount has a claim-specific defect, and another plaintiff's qualifying claim can still anchor the case. A citizenship overlap between a plaintiff and a defendant has an action-wide effect, and no claim remains to anchor anything. Running the screen in a fixed order keeps the two defects from blurring.

Exam Analysis Steps

Because the anchor question comes before any question about relatedness, it is best run as a screen over the complaint. The steps are these:

List every claim in the action and the statute that would give each claim original jurisdiction on its own, such as § 1331 for a federal question or § 1332 for diversity.
If any claim rests on diversity, test complete diversity across the whole action first, because one plaintiff who shares citizenship with one defendant removes original diversity jurisdiction over every claim.
If diversity is complete, test the amount in controversy plaintiff by plaintiff and claim by claim, without adding together the claims of separate plaintiffs.
If at least one claim survives these tests, treat it as the anchor and move on to relatedness. If none survives, stop, because the action must be dismissed for lack of subject-matter jurisdiction.

Same Case or Controversy

Section 1367(a) sets its standard of relatedness in a single phrase: the added claims must be “so related to claims in the action within such original jurisdiction that they form part of the same case or controversy under Article III of the United States Constitution.”²¹ The statute does not say what counts as one case or controversy, but the Supreme Court held in City of Chicago v. International College of Surgeons that the phrase carries the meaning it had in Gibbs.²² The inference is natural. When Congress wrote the phrase, it was already the label in pendent and ancillary jurisdiction cases for the Gibbs test of a single constitutional case, and a legislature that borrows a familiar standard ordinarily means the familiar standard.²³ Relatedness therefore calls for no new test. The common-nucleus inquiry developed earlier in the chapter governs, and a court compares the events underlying each claim.

The joinder rules and the statute answer different questions, and a counterclaim must satisfy both. Rule 13 sorts counterclaims by whether they arise out of “the transaction or occurrence” that is the subject matter of the plaintiff's claim, and those that do are compulsory.²⁴ That sorting tells a party what it must or may plead. The statute tells the court whether it has power over what was pleaded, and a pleading rule operates inside a court that already has authority, so it cannot create authority the court lacks. A student who reasons that the rules let a defendant file any counterclaim has answered the procedural question and left the jurisdictional one untouched. That gap is where exam answers on counterclaims lose points.

The two standards line up closely, which is why counterclaims usually sort easily. Most courts decide whether a counterclaim is compulsory with the logical relation test, a loose standard that permits “a broad realistic interpretation in the interest of avoiding a multiplicity of suits” and that finds a logical relationship when the claim and counterclaim arise from the same aggregate of operative facts.²⁵ A counterclaim growing out of the same events as the main claim therefore fits comfortably within the same case or controversy. A permissive counterclaim lacks that connection, so it falls outside the grant and needs a jurisdictional basis of its own.²⁶

Hypothetical Illustration

Browning, a New York citizen, sues Blake, an Ohio citizen, for $100,000 for her injuries in a car collision, and the claim satisfies § 1332 on its own. Blake answers with a $25,000 counterclaim for damage Browning did to his land in a trespass four months before the collision. The trespass involves a different day, different witnesses, and a different harm, so the counterclaim is permissive, falls outside the same case or controversy, and misses the amount required by § 1332. The court has no power over it. Had Blake instead counterclaimed for $35,000 for his own injuries in the collision, the counterclaim would be compulsory, would rest on the same driving, the same witnesses, and the same medical proof, and would fall within supplemental jurisdiction despite its amount.

The trespass counterclaim fails at the constitutional step. Gibbs admits only state claims that arise from the same nucleus of operative fact as the main claim, and § 1367(a) draws its boundary at the same place, so a claim that fails the constitutional test cannot satisfy the statutory one.²⁷ The injury counterclaim lacks a basis of its own, because it rests on state law and falls below the amount, yet it enters the case because it arises from the same accident as the main claim. The court has constitutional power to hear it, and § 1367(a) supplies the statutory authority.²⁸ The diversity-only limit in § 1367(b) does not interfere, since that subsection withholds supplemental jurisdiction only over certain claims by plaintiffs, and here the defendant asserts the claim.²⁹ A later section returns to the diversity limits.

Relatedness matters only to a claim that has no ticket of its own. Suppose Blake's unrelated counterclaim were instead for $30,000 for infringement of a patent that Blake holds. The court could not take it under § 1367(a), because it shares nothing with the collision. But the district courts have exclusive subject matter jurisdiction over cases involving a U.S. patent under 28 U.S.C. § 1338, so the claim stands on an original-jurisdiction basis of its own.³⁰ The court hears it as a freestanding claim, and its distance from the collision no longer matters. An unrelated state-law counterclaim for more than $75,000 between diverse parties would stand on § 1332 in the same way. Whether an unrelated counterclaim survives therefore depends on whether it has an independent basis, which the trespass claim lacks and the patent claim has.

Exam Analysis Steps

Because relatedness matters only when a claim has no ticket of its own, a counterclaim problem is best run in an order that lets the first successful step end the inquiry. The steps are these:

Confirm that the plaintiff's claim is an anchor with original jurisdiction under § 1331, § 1332, or another statute.
Ask whether the counterclaim has an independent basis of its own, such as a federal question or diversity with a sufficient amount, and stop if it does, because supplemental jurisdiction is then unnecessary.
If it has no independent basis, compare the events the counterclaim must prove with the events behind the plaintiff's claim, and treat a counterclaim arising from the same transaction or occurrence as part of the same case or controversy.
If the counterclaim is permissive and unrelated, conclude that it falls outside the statute and must be dismissed.

Additional Parties

The relatedness standard decides which claims may ride along with an anchor claim, and the last sentence of § 1367(a) decides who may be a party to them: “Such supplemental jurisdiction shall include claims that involve the joinder or intervention of additional parties.”³² A related claim therefore keeps its place in the case even when the person defending it was never named in the anchor claim, or when the person asserting it was not an original plaintiff. The sentence reaches parties who enter by joinder or by intervention, and in each instance the question remains whether the claim involving the new party is part of the same case or controversy as the anchor claim.

Congress wrote the sentence because one set of events can create federal liability for one actor and only state-law liability for another. If the court's power stopped at the parties to the anchor claim, the plaintiff would have to try the second dispute elsewhere, and the efficiencies that supplemental jurisdiction exists to achieve would be lost.³³ The requirement of relatedness keeps the extension from running loose, because a person with no connection to the federal dispute does not enter merely because someone prefers a federal forum. The sentence also settles the old problem of pendent parties, as when a plaintiff has a federal claim against one defendant and a state claim against another. Finley had refused to permit that kind of joinder, and all concede that one purpose of § 1367 was to change that result.³⁴

The Supreme Court confirmed this reading in Allapattah, where it rejected the argument that the presence of additional parties removes a civil action from the scope of § 1367(a). The argument fails first because the statute's last sentence itself contemplates supplemental jurisdiction over additional parties. It fails second because it would leave the result in Finley undisturbed. Finley was a Federal Tort Claims Act suit against a federal defendant, joined with state-law claims against additional defendants not otherwise subject to federal jurisdiction, and yet all concede that one purpose of § 1367 was to change that result.³⁵ A reading that made the anchor vanish whenever an extra party appeared would have left the last sentence with nothing to do.

The principal's citizenship and the small amount of the claim do not matter in this scene, because those features defeat only a claim that must stand on diversity, and this claim rides on a federal anchor. The usual exam error is to deny jurisdiction over an added defendant in a federal-question case because that defendant is not diverse from the plaintiff. The same reasoning admits an added plaintiff. A second employee dismissed in the same episode who joins to assert the same state-law claim against the principal brings a claim within the last sentence, and the diversity-only limits of § 1367(b) are no obstacle, because they operate only in an action of which original jurisdiction is founded solely on § 1332.³⁶ The added party's claim must still pass the relatedness test, so a claim against the principal over an unrelated personal loan would fail for the same reason the trespass counterclaim failed earlier.

An exam writer who wants to test this sentence usually keeps the added defendant and changes the anchor. Suppose a plaintiff has two $40,000 claims against D1, which aggregate to $80,000 and satisfy § 1332, and tries to bring in D2 on a single $40,000 claim. Most courts will not allow the claim against D2, because the plaintiff's total claims against D2 do not exceed $75,000 and supplemental jurisdiction does not apply.³⁷ The added party in both scenes is a defendant facing a state-law claim worth less than $75,000, so the difference lies in what anchors the case. A federal-question anchor places the dispute outside the diversity-only limits, while a diversity-only anchor leaves it subject to them.³⁸ The grant in subsection (a) is therefore a default that subsection (b) cuts back for certain claims by plaintiffs, and the next section takes up those limits.