Rule 12(b)(1) Motion to Dismiss Standard

Fed. R. Civ. P. 12(b)(1) motions for lack of subject matter jurisdiction generally take one of two forms: (1) a facial attack on the sufficiency of the complaint's allegations as to subject matter jurisdiction; or (2) a challenge to the actual facts upon which subject matter jurisdiction is based.

• court reviewing facial challenge must accept plaintiff's factual allegations regarding jurisdiction as true
• court reviewing factual challenge may not presume plaintiff's allegations are true; court has discretion to consider affidavits, other docs, and limited evidentiary hearing to resolve disputed jurisdictional facts
• plaintiffs bear burden of proving that jurisdiction is proper
• because fed courts are courts of limited jurisdiction, the presumption is against fed jurisdiction
• for purposes of determining whether diversity jurisdiction exists, a person is a "citizen" of the state in which he or she is "domiciled"
• for adults, domicile is established by physical presence in a place in connection with a certain state of mind concerning one's intent to remain there