Supplemental Jurisdiction - Ancillary Jurisdiction

Ancillary Jurisdiction

Ancillary jurisdiction is a form of supplemental jurisdiction that allows a United States federal court to hear non-federal claims sufficiently logically dependent on a federal "anchor claim" (i.e., a federal claim serving as the basis for supplemental jurisdiction), despite that such courts would otherwise lack jurisdiction over such claims. Ancillary jurisdiction differs from pendent jurisdiction in that pendent jurisdiction requires the federal and non-federal claims to arise from a "common nucleus of operative fact," (per "United Mine Workers of America v. Gibbs") not to be logically interdependent. Like pendent jurisdiction, a federal court can exercise ancillary jurisdiction if the anchor claim has original federal jurisdiction either through federal-question jurisdiction or diversity jurisdiction.

Areas where ancillary jurisdiction can be asserted include counterclaims (Fed. R. Civ. P. 13), cross-claims (Fed. R. Civ. P. 13), impleader (Fed. R. Civ. P. 14), interpleader (Fed. R. Civ. P. 22) and interventions (Fed. R. Civ. P. 24). Impleader claims are a paradigmatic example of ancillary jurisdiction, given the tendency of such claims to arise under state contract law, but be entirely dependent on the original claim.

"Moore v. New York Cotton Exchange" and "Owen Equipment & Erection Co. v. Kroger" are seminal cases relating to ancillary jurisdiction.

Ancillary jurisdiction has been replaced entirely by supplemental jurisdiction, per 28 U.S.C. § 1367(b), part of the U.S. supplemental jurisdiction statute.