Rule 19. Required Joinder of Parties
(a) Persons Required to Be Joined if
(1) Required Party. A
person who is subject to service of process and whose
joinder will not deprive the court of subject-matter
jurisdiction must be joined as a party if:
(A) in that
person's absence, the court cannot accord complete
relief among existing parties; or
(B) that person claims an interest relating to the
subject of the action and is so situated that disposing of
the action in the person’s absence may:
(i) as a practical matter impair or impede the
person's ability to protect the interest; or
(ii) leave an existing party subject to a substantial
risk of incurring double, multiple, or otherwise
inconsistent obligations because of the interest.
(2) Joinder by Court Order.
If a person has not been joined as required, the court must
order that the person be made a party. A person who refuses
to join as a plaintiff may be made either a defendant or,
in a proper case, an involuntary plaintiff.
(3) Venue. If a joined party
objects to venue and the joinder would make venue improper,
the court must dismiss that party.