The Statutory Grant: § 1367(a)

Gibbs established that Article III allows a federal court to hear a state claim that shares a common nucleus of operative fact with a substantial federal claim. Constitutional power alone does not let a court act, however, because federal courts have no jurisdiction without statutory authorization. That gap produced a sharp conflict. In Finley v. United States a plaintiff sued the Federal Aviation Administration under the Federal Tort Claims Act and tried to add related claims against other defendants arising from the same events. The Supreme Court held that the district court had no statutory basis for the added-party claims, because a grant of jurisdiction over claims involving particular parties does not by itself confer jurisdiction over additional claims by or against different parties.¹ The Court also observed that Congress could change whatever it said about the scope of a jurisdictional statute, and in 1990 Congress did so by passing the Judicial Improvements Act, which enacted 28 U.S.C. § 1367.²

Subsection (a) is the broad grant at the center of that statute. It gives the district courts supplemental jurisdiction over all other claims so related to claims within the court's original jurisdiction that they form part of the same case or controversy under Article III, and it adds that this jurisdiction includes claims involving the joinder or intervention of additional parties.³ The provision therefore has three operative parts: an original-jurisdiction threshold, a same-case-or-controversy requirement, and an express reach to additional parties. It also opens with a warning, since the grant applies except as provided in subsections (b) and (c) or as expressly provided otherwise by federal statute. Those exceptions are the diversity limits and the court's discretion to decline, which later sections take up. The sections below take the three operative parts in order, beginning with the requirement that something must already be in federal court.

The Original-Jurisdiction Threshold

Subsection (a) operates only "in any civil action of which the district courts have original jurisdiction."⁴ The words mean that supplemental jurisdiction can only be attached to something. At least one claim in the action must satisfy a standalone basis for federal jurisdiction, such as federal question jurisdiction under § 1331 or diversity jurisdiction under § 1332. That anchor claim carries the action into federal court, and the related claims then travel with it. The statute supplements a case that already belongs in federal court and cannot bring a case into federal court by itself.⁵

The reason for the threshold follows from the limited character of federal courts. Federal jurisdiction is decided claim by claim, so every claim in the action needs some basis, and the only thing that can excuse a claim from having its own is a connection to a claim that does.⁶ Where no claim has an independent basis, nothing exists for the related claims to attach to. Incomplete diversity shows the point, because it destroys original jurisdiction over every claim in the action, and so leaves no supplemental jurisdiction to exercise.⁷

The threshold is also easier to satisfy than it first appears. In Exxon Mobil Corp. v. Allapattah Services, Inc. the Court reasoned that when a well-pleaded complaint contains at least one claim within original jurisdiction, with no other relevant jurisdictional defects, the court has original jurisdiction over a "civil action" within the meaning of § 1367(a), even though the complaint also includes claims that lack it.⁸ Suppose a plaintiff sues a former employer in federal court under a federal anti-discrimination statute and adds a state wrongful-discharge claim over the same firing. The federal claim is the anchor, so subsection (a) is available. Now suppose the same plaintiff sues only on the state claim and the parties are citizens of the same state. No claim satisfies § 1331 or § 1332, so the threshold fails and subsection (a) has nothing to supplement.

Same Case or Controversy

Once an anchor claim exists, subsection (a) reaches claims so related to it that they form part of the same case or controversy under Article III. The statute does not define that phrase, but it has been read to carry the same meaning it had in Gibbs.¹⁰ The inference is natural, because Congress knew that courts had long used the Gibbs test to decide what counted as a single constitutional case in pendent and ancillary jurisdiction, and it chose the same concept to mark the limit of the new grant. A supplemental claim is therefore related to the anchor claim when the two derive from a common nucleus of operative fact.¹¹

A plaintiff fired because of religion who sues under Title VII and adds a state wrongful-discharge claim alleging the same religious motive shows the standard working. The state claim does not arise under § 1331, and the parties may share citizenship, so it has no basis of its own. Both claims rest on one event, the firing, so they share a common nucleus of operative fact and subsection (a) is satisfied.¹² Change one fact and the answer changes. If the same plaintiff also added a claim that the employer owes an unrelated debt, that claim would not grow out of the firing, so it would fall outside the same case or controversy and would need its own jurisdictional basis. The joinder rules use a similar same-transaction-or-occurrence standard, which is why a claim that is properly joined under those rules will usually satisfy the jurisdictional test as well.¹³

The statute and the constitutional test are separate requirements, and both must be met. Even where claims arise from the same nucleus of operative facts and it would make good litigation sense to hear them together, a court cannot exercise jurisdiction without a statutory grant, and Congress may withhold one.¹⁴ That is why the statute was needed even though Gibbs already described the constitutional limit. The authority Congress supplied is very broad, and in most situations it extends to the outer boundary of the constitutional case before the court.¹⁵

Claims Involving Additional Parties

The last sentence of subsection (a) provides that supplemental jurisdiction includes claims that involve the joinder or intervention of additional parties.¹⁷ This sentence reverses the result in Finley. The pre-1990 cases had drawn a line between additional claims and additional parties. In Aldinger v. Howard a plaintiff with a federal civil rights claim against county officials tried to add a related state-law claim against the county itself, and the Court refused because Congress had implicitly declined to extend jurisdiction to a party that could not be sued under the federal civil rights statute.¹⁸ Finley then extended that caution by declining to read jurisdictional statutes broadly where new parties were involved.¹⁹ The 1990 statute is explicit about parties, and it is understood to allow what are called pendent parties, as when a plaintiff has a federal claim against one defendant and a related state claim against another.²⁰

The reason for the express language is practical. Without it, a plaintiff injured in a single accident could be forced to litigate the same events twice, with the federal claim in one court system and the state claims against other defendants in another, even though the federal claim is within exclusive federal jurisdiction. The hornbook-style fact pattern is easy to picture. Suppose a plaintiff whose relatives died when a small plane struck power lines near an airfield sues the United States under the Federal Tort Claims Act for inadequate runway lights, then adds state tort claims against the city and the private company that maintained the lines. There is no diversity and no federal question against the new defendants, but their claims arise from the same chain of events as the federal claim, so the last sentence of subsection (a) supports them.²¹ A second illustration is a borrower who sues a lender in an Ohio federal court under a federal lending statute and then adds the Ohio car dealer, a fellow Ohio citizen, on a state-law claim for $20,000. Without supplemental jurisdiction, the claim against the dealer would fail for lack of both diversity and amount in controversy, yet it goes forward because it arises from the same transaction as the federal claim.²²

The added-party language does not override every other limit in the statute. It remains subject to the opening exceptions, and in particular subsection (b) restricts certain plaintiff-side claims when original jurisdiction rests only on diversity. The statute also cannot be used to join parties in a way that would defeat complete diversity, because incomplete diversity destroys original jurisdiction over the whole action and leaves nothing to which supplemental jurisdiction can adhere.²³

The Original-Jurisdiction Threshold

The first words of subsection (a) set a condition that every supplemental-jurisdiction problem must satisfy before anything else is asked. The grant operates only "in any civil action of which the district courts have original jurisdiction."²⁵ Original jurisdiction means jurisdiction that rests on a standalone statutory basis, such as federal question jurisdiction under § 1331 or diversity jurisdiction under § 1332, without help from any other claim. The phrase tells the reader that supplemental jurisdiction has to be attached to something. At least one claim in the action must already qualify for federal court on its own terms, and the related claims then travel into federal court with it.²⁶

The reason for this threshold comes from the way federal jurisdiction is measured. Federal courts have limited jurisdiction, and the analysis proceeds claim by claim, so each claim in a complaint needs some basis for being heard.²⁷ Supplemental jurisdiction is the one device that can excuse a claim from having a basis of its own, and the only thing that justifies the excuse is a close connection to a claim that does have one. The statute exists to keep a case that already belongs in federal court from being split in two. If no claim qualifies independently, there is no federal case to protect, and extending jurisdiction would turn the federal courts into forums for purely state-law disputes. The point can be put as a sequence: supplemental jurisdiction may never be exercised on its own, and it can only supplement jurisdiction already taken under § 1331, § 1332, or another original-jurisdiction statute.²⁸

A matched pair of invented facts shows which fact decides the question. Suppose a plaintiff who is a citizen of Texas sues a Florida defendant for $125,000 over a business deal gone wrong, and adds a second state-law claim for $10,000 arising from the same deal. The first claim satisfies diversity, because the parties are citizens of different states and the amount exceeds $75,000.²⁹ That claim is the anchor, so the court has original jurisdiction over the civil action, and subsection (a) is available for the smaller claim, which could not satisfy the amount requirement by itself. Now change one thing: two citizens of Ohio sue each other, and both of their claims arise under state law. No claim has a federal question, and diversity is missing because the parties share a state. Nothing in the action has an independent basis, so there is nothing for the related claims to attach to, and the whole suit must be dismissed for lack of subject-matter jurisdiction.³⁰

The threshold also raises a question that later sections must answer. A complaint may contain some claims that satisfy the jurisdictional requirements and others that do not, particularly in diversity cases where one plaintiff's claim falls short of the amount in controversy. Whether the court has original jurisdiction over a "civil action" in that situation is the problem that Exxon Mobil Corp. v. Allapattah Services, Inc. addresses, and it is taken up after the diversity limits of subsection (b).

Same Case or Controversy

Once an anchor claim is in place, the statute asks how closely each remaining claim is tied to it. Subsection (a) reaches only claims "so related" to the claims within original jurisdiction that "they form part of the same case or controversy under Article III."³² The statute does not define that phrase, but it is read to mean essentially what Gibbs meant by a single constitutional case: the federal and state claims derive from a common nucleus of operative fact, so that a plaintiff would ordinarily be expected to try them all in one judicial proceeding.³³ Because Congress borrowed an existing constitutional standard, the relatedness question under the statute is answered by the same inquiry that marked the constitutional limit before the statute existed.

The reason relatedness is the dividing line comes from what supplemental jurisdiction is meant to save. A federal court that is already adjudicating one set of events has already paid the cost of learning the facts, assembling the witnesses, and applying the law to them. Hearing a second claim that grows out of the same events adds little, since the parties would ordinarily litigate both together anyway. A claim about unrelated events offers no such saving, because the court would have to start over on a new set of facts, and so the justification for excusing the claim from having its own jurisdictional basis disappears.

A matched pair of examples shows which fact does the work. Suppose a driver sues for $100,000 over a collision, and the defendant files a compulsory counterclaim for $10,000 in property damage from the same collision. The counterclaim rests on state law and falls below the amount-in-controversy requirement, so it has no basis of its own. It arises from the same accident as the main claim, however, so it shares a common nucleus of operative fact, and subsection (a) supplies the statutory authority to hear it.³⁴ Now change what the counterclaim is about. If the defendant instead asserts a permissive counterclaim for $10,000 on an unrelated contract dispute, no common nucleus links it to the collision. It fails the Gibbs analysis at the constitutional level, and because the statute defines its reach by the same test, there is no need to ask whether the statute would otherwise grant jurisdiction.³⁵

The line can be a fine one when the connection is causal but distant. Imagine a man arrested after a dispute who sues the arresting officer under § 1983 and adds a state-law assault claim over the arrest itself. The assault claim arises from the same events as the federal claim, so it is within the grant. If he also adds a claim over a debt that preceded the arrest, any causal relationship between the debt and the arrest is probably too attenuated to make the two part of one nucleus of facts, so the debt claim falls outside the same case or controversy.³⁶

Relatedness matters only for a claim that lacks a jurisdictional basis of its own. If an unrelated counterclaim independently arises under federal law, as a patent counterclaim does under §§ 1331 and 1338(a), the court has original jurisdiction over it and does not need supplemental jurisdiction at all.³⁷ The unrelated state-law counterclaim fails and the unrelated patent counterclaim succeeds for the same reason in reverse: the first needs the relatedness bridge and cannot cross it, while the second never needed the bridge.

The same-case-or-controversy test also resembles the same-transaction-or-occurrence standard used in the joinder rules and in claim preclusion, though the two are not exactly identical. Gibbs is generally understood to be satisfied when the claims arise from the same transaction or occurrence, but a common nucleus may reach some more loosely related situations as well.³⁸ In the preclusion setting, the tests look nearly the same, yet some federal courts treat the jurisdictional test as the more spacious one. A state claim that qualified for supplemental jurisdiction might therefore still escape preclusion if the claimant left it out of the first suit.³⁹ The practical rule is that a claim properly joined as arising from the same transaction will usually satisfy the jurisdictional test, but a court may draw the two lines in slightly different places.

Claims Involving Additional Parties

A plaintiff with a federal claim against one defendant often has a closely related state-law claim against someone else. The question is whether that second defendant can be sued in the same federal action when no claim against that defendant has its own jurisdictional basis. The last sentence of § 1367(a) answers it: supplemental jurisdiction "shall include claims that involve the joinder or intervention of additional parties."⁴¹ The sentence makes sense only against the line of cases it was written to overturn.

Before 1990, the Supreme Court allowed a federal court to hear an added state-law claim against a party already in the case, but it refused to bring in a new party the same way. In Aldinger v. Howard a plaintiff sued county officials under 42 U.S.C. § 1983 and added a state-law claim against the county itself. The Court held that a federal court must find not only that Article III permits jurisdiction over a new party, but also that Congress, in the statutes conferring jurisdiction, has not negated it. Because the county could not be sued under § 1983, Congress had implicitly declined to extend federal jurisdiction to it.⁴² Finley v. United States hardened that caution. A plaintiff suing the Federal Aviation Administration under the Federal Tort Claims Act tried to add related claims against other defendants, and the Court held that a grant of jurisdiction over claims involving particular parties does not itself confer jurisdiction over claims by or against different parties.⁴³ Finley also reminded Congress that it could change the result, and Congress did so the following year by enacting § 1367.⁴⁴

The added-party sentence is that change. It supplies the express statutory authorization that Finley required, so a court with an anchor claim may now hear related claims against parties who have no independent basis of their own. The reason is the one that the older cases themselves hinted at. A single event often involves several wrongdoers, and if the federal claim reaches only one of them, the plaintiff would otherwise have to try the same facts twice, once in federal court and once in state court. The hardship is sharpest when federal jurisdiction over the anchor claim is exclusive, because then no state court can hear the whole dispute at all.⁴⁵

Two invented fact patterns show where the sentence applies and where it stops. Suppose a student sues a school district under § 1983 and adds a state-law negligence claim against the principal, who is a citizen of the student's own state. The § 1983 claim is the anchor under § 1331. The claim against the principal arises from the same events, so it forms part of the same Article III case, and the missing diversity and amount in controversy do not matter. The same result follows for a patent holder who sues one infringer in federal court, where jurisdiction is exclusive, and adds a state-law claim against a non-diverse co-actor. Section 1367(b) does not apply there, because it addresses only cases where original jurisdiction rests solely on diversity.⁴⁶ A borrower who sues a finance company under a federal lending statute and adds the car dealer on a related $20,000 state-law claim stands in the same position.⁴⁷

Now change the source of the anchor. If the only original-jurisdiction claim is a diversity claim, an added plaintiff-side claim against a new party may run into subsection (b), which the next section takes up. Also, adding a party who is a citizen of the same state as an opposing party defeats complete diversity. Without complete diversity there is no original jurisdiction over any claim in the action, so nothing remains to which supplemental jurisdiction can attach.⁴⁸ The added-party language therefore enlarges what a court can hear around an anchor claim, but it cannot create an anchor and it remains subject to the exceptions in subsections (b) and (c).⁴⁹