20 C.F.R. § 1002.307 – What is the proper venue in an action against a State or private employer?

(a) If an action is brought by the Attorney General against a State, the action may proceed in the United States district court for any district in which the State exercises any authority or carries out any function.
(b) If an action is brought against a private employer, or a political subdivision of a State, the action may proceed in the United States district court for any district in which the employer maintains a place of business.