ancillary jurisdiction

Ancillary jurisdiction allows a federal court to hear a claim that would normally be outside of its subject-matter jurisdiction if it is substantially related to a second claim that is within the court's jurisdiction . A claim comes within a federal court’s ancillary jurisdiction when it bears "a logical relationship to the aggregate core of operative facts " of the main claim, and the main claim meets the requirements of federal question jurisdiction , or diversity jurisdiction .

See: e.g., Revere Copper Brass v. Aetna Cas. Sur. Co. (1970) ; Hendrickson v. U.S 791 F.3d 354 (2015)

[Last reviewed in November of 2024 by the Wex Definitions Team ]

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