Also known as: ancillary jurisdiction · pendent jurisdiction · ancillary/pendent jurisdiction · supplemental jurisdiction
Written by attorneys · grounded in primary & secondary sources — see below
Nonstatutory doctrines authorizing federal courts to exercise jurisdiction over related claims that form part of the same case or controversy as a claim within the court's original jurisdiction. The doctrines require at least one anchor claim satisfying statutory jurisdictional requirements before extending to additional related claims.
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Alfred Ashford sued Arcadia Retail in federal court under diversity jurisdiction for breach of a supply contract seeking $90,000. Austin Abbott joined as a co-plaintiff asserting a related breach claim for only $40,000 arising from the same shipment dispute. The court exercised supplemental jurisdiction over Abbott's claim because it shared a common nucleus of operative fact with Ashford's claim that met the amount-in-controversy requirement.
Alexis Archer filed a federal copyright infringement suit against Apollo Energy in district court. Alexandra Armstrong asserted a state unfair-competition claim in the same action arising from the identical unauthorized use of protected materials. The court exercised supplemental jurisdiction over the state claim because it formed part of the same case or controversy under Article III.
Aaron Adams brought a federal securities claim against Argonaut Shipping in district court. Albert Allen added a state-law fraud claim based on the same misleading disclosures and transaction documents. The court exercised pendent jurisdiction over the state claim because both claims derived from a common nucleus of operative fact.
Arcadia Retail sued Artemis Logistics in a diversity action for unpaid invoices exceeding $75,000. Artemis impleaded Apollo Energy under Rule 14 for contribution on the same contract. The court lacked supplemental jurisdiction over the impleader claim because exercising it would destroy complete diversity between the original parties.
Alfred Ashford sued Argonaut Shipping in admiralty for cargo damage. Austin Abbott asserted a related state-law indemnity claim against the same vessel arising from the identical voyage. The court exercised ancillary jurisdiction over the indemnity claim to avoid piecemeal litigation of the single maritime incident.
Alexis Archer sued Apollo Energy for breach of a licensing agreement. Apollo asserted a compulsory counterclaim for trademark infringement arising from the same agreement and product line. The court exercised ancillary jurisdiction over the counterclaim because it arose from the identical transaction or occurrence as the original claim.
Ancillary and pendent jurisdiction were judicially created doctrines that permitted federal courts to hear related claims lacking an independent basis for federal jurisdiction. Congress codified both doctrines in 28 U.S.C. § 1367(a) under the single heading of supplemental jurisdiction.
Supplemental jurisdiction reaches additional plaintiffs' claims that share a common nucleus of operative fact with an anchor claim meeting the amount-in-controversy requirement, provided complete diversity is preserved. The Supreme Court confirmed this application in diversity actions where at least one plaintiff's claim satisfies the jurisdictional amount.
…satisfy the jurisdictional requirements.” III Our interpretation is consistent with the historical development of ancillary and pendent jurisdiction. Before the enactment of §1367, the Court had recognized that in a diversity case, a court could exercise ancillary jurisdiction over claims by intervenors and over compulsory counterclaims…
…principles of res judicata and collateral estoppel caution the civil plaintiff against splitting his case. The doctrine of pendent jurisdiction
…496 (1941). This rests upon a perception of the constitutional and congressional plan underlying the creation of diversity and pendent jurisdiction
…because Siler v. Louisville & Nashville R. Co. , 213 U. S. 175 (1909), an important case in the development of the doctrine of
…of them "pendent" to its
A court may decline supplemental jurisdiction when the claim raises a novel or complex issue of state law, when state claims substantially predominate, when the anchor claim has been dismissed, or when other compelling reasons exist. These discretionary grounds appear in 28 U.S.C. § 1367(c).
Supplemental jurisdiction applies in diversity cases but is limited by 28 U.S.C. § 1367(b), which bars jurisdiction over claims by plaintiffs against parties joined under Rules 14, 19, 20, or 24 when exercising jurisdiction would be inconsistent with the requirements of section 1332.
Claims share a common nucleus when they arise from the same transaction or occurrence and a plaintiff would ordinarily be expected to try them in one proceeding. This standard originated in pendent-jurisdiction cases and continues under the supplemental-jurisdiction statute.