The Federal Rules of Civil Procedure
(1) By a Plaintiff. Persons with claims that may expose a plaintiff to double or multiple liability may be joined as defendants and required to interplead. Joinder for interpleader is proper even though:
(A) the claims of the several claimants, or the titles on which their claims depend, lack a common origin or are adverse and independent rather than identical; or
(B) the plaintiff denies liability in whole or in part to any or all of the claimants.
(2) By a Defendant. A defendant exposed to similar liability may seek interpleader through a crossclaim or counterclaim.
(b) Relation to Other Rules and Statutes. This rule supplements—and does not limit—the joinder of parties allowed by Rule 20. The remedy this rule provides is in addition to—and does not supersede or limit—the remedy provided by 28 U.S.C. §§1335, 1397, and 2361. An action under those statutes must be conducted under these rules.