Concept

Related Statutory and Practical Points

Supplemental jurisdiction

Supplemental jurisdiction does not end when a court finds that it has power and decides to use it. Several consequences follow from the grant in § 1367(a) and the discretion in § 1367(c). One is the time-bar problem a plaintiff faces if the court declines a state claim. A second is the question of which law governs a state claim once it sits in federal court. A third is what happens to a related claim that the plaintiff never asserted. This section takes those points in turn and ends with a checklist that ties the whole chapter together.

Tolling and Definitions

Because § 1367(c) lets a district court decline a claim it has the power to hear, a plaintiff who joins a state claim to a federal one takes a risk. The court may dismiss the state claim without prejudice, meaning without deciding its merits, and the plaintiff must then refile in state court. If the limitations period ran out while the case was pending in federal court, the dismissal would destroy the claim. Section 1367(d) removes that risk by tolling the limitations period, which means pausing the clock. The period for any claim asserted under subsection (a) is tolled while the claim is pending and for 30 days after it is dismissed, unless state law provides a longer tolling period.¹ The tolling also covers any other claim in the same action that is voluntarily dismissed at the same time as, or after, the dismissal of the subsection (a) claim.²

Two features of the provision shape how it works. First, the plaintiff always has at least 30 days to refile, even if only a few days remained on the state limitations period when the federal suit was filed.³ Second, the state period is not merely extended but held in abeyance for the whole time the claim was in federal court, so the plaintiff does not lose the time spent there. Claims against a State or a state agency are an exception to this saving rule.⁴ Suppose a plaintiff sues an employer in federal court on a federal statutory claim and adds a state contract claim. The federal claim is dismissed early, and the court declines the contract claim under § 1367(c)(3). The plaintiff can refile the contract claim in state court within 30 days, or within any longer period state law allows, without a limitations defense based on the months spent in federal court. Compare a plaintiff who never pleaded the contract claim in the federal action at all. That plaintiff has no pending claim to toll, and the ordinary limitations period kept running.

Subsection (e) supplies a definition that applies throughout the section. The term State includes the District of Columbia, the Commonwealth of Puerto Rico, and any territory or possession of the United States.⁵ The definition matters when a provision such as the tolling rule refers to state law, because the law of those places counts the same way.

Law Applied to Supplemental Claims

Supplemental jurisdiction answers only whether the federal court may hear a claim. It does not say what law decides the claim. A claim that rides in on supplemental jurisdiction does not arise under federal law, which is exactly why it needed supplemental jurisdiction in the first place. Federal law therefore does not govern it, and under Erie it is governed by state law, including the state's conflict-of-laws rules.⁷ The same conclusion follows from the logic of the Rules of Decision Act, which requires recourse to state law whenever a point arises that federal law does not govern. That is why Erie applies when a state-law claim reaches federal court through supplemental jurisdiction, even though most Erie questions arise in diversity cases.⁸ Where the court exercises supplemental jurisdiction over a state-created claim, state substantive law controls it.⁹

The reason is that supplemental jurisdiction supplies a forum, not a new source of substantive rights. A plaintiff should not gain a different substantive result on a state claim merely because it was heard next to a federal claim. The same reasoning limits what supplemental jurisdiction cures. It resolves subject-matter jurisdiction alone, and it does not eliminate the need for personal jurisdiction over each party or for service of process.¹⁰ Venue is treated more generously, since venue requirements ordinarily need not be satisfied for a claim or party that is properly within supplemental jurisdiction.¹¹ Imagine a federal court hearing a state negligence claim alongside a federal civil rights claim. The negligence elements and defenses come from state law, yet the court still needs a valid basis to reach each defendant personally.

Link to Claim Preclusion

The relatedness test for supplemental jurisdiction closely resembles the transaction test used to decide whether an omitted claim is barred by claim preclusion. A claim without its own jurisdictional basis must be part of the same case or controversy as an anchor claim to come within supplemental jurisdiction, and a claim left out of a first suit is barred from a second when it arises from the same transaction or occurrence.¹³ In principle, then, a claim that could have been tried together with the federal claim is usually one that should have been. Some federal courts treat the case-or-controversy test as broader than the transaction test, so a claim that would have qualified for supplemental jurisdiction might still escape preclusion if it was omitted.¹⁴

The discretion in § 1367(c) complicates this. A plaintiff in federal court generally must assert supplemental claims or risk losing them to preclusion. If the court hears the state claim, the benefits of joint litigation are realized. If the court refuses to hear it, the plaintiff is not barred from suing in state court, because the claim could not be heard in the first action.¹⁵ The plaintiff's safe course is to plead the claim and, if necessary, let the court decline it. Suppose one plaintiff sues in federal court on a federal civil rights claim and pleads a related state battery claim, and the court declines the battery claim. That plaintiff can sue on it in state court. Another plaintiff, who never pleaded the battery claim in the federal action, may find the later state suit barred, since the potential benefits of joint litigation were lost through the plaintiff's own neglect.¹⁶

Exam Checklist

Exam Analysis Steps

Because supplemental jurisdiction involves a grant, a limit, and a discretion, it is best run in order. Each step answers a separate question, and an early "no" ends the analysis for that claim. The steps are these:

Identify the anchor claim, meaning a claim that satisfies a standalone basis such as federal question or diversity with the required amount, and recognize that if no claim does, the whole suit is dismissed and supplemental jurisdiction never arises.¹⁸
Ask whether the additional claim or party forms part of the same case or controversy as the anchor claim, which is satisfied when the claims derive from a common nucleus of operative fact, and remember that § 1367(a) reaches claims involving additional parties.¹⁹
If original jurisdiction rests solely on diversity, apply § 1367(b), which withholds jurisdiction over certain plaintiff-side claims against persons joined under Rules 14, 19, 20, or 24 and over claims by persons joined or intervening as plaintiffs under Rules 19 or 24; additional defendants brought in by the plaintiff therefore need their own basis, while crossclaims between defendants are covered.²⁰
For additional plaintiffs in a diversity case, apply Exxon Mobil Corp. v. Allapattah Services, Inc.: if one plaintiff satisfies the amount in controversy and complete diversity holds, other plaintiffs with smaller claims may proceed, including class members.²¹
Finally, consider whether the court may decline under § 1367(c), and remember that the court is not required to decline when a ground is present, so tolling under § 1367(d) protects the plaintiff if it does.²²

The order matters because the steps do different jobs. Steps one through four decide whether the court has power, and step five decides whether it should use that power. Only after that does the law governing the claim become relevant, and it will be state law for any state-created claim.