(a) Persons to Be Joined. Except as otherwise provided by law, a person who is subject to service of process shall be joined as a party in the action if in the person's absence

The court shall order that the person be made a party if not joined as required by this section. If the person should join as a plaintiff but refuses to do so, the person shall be made either a defendant or, in a proper case, an involuntary plaintiff.

(b) Reasons for Nonjoinder. A pleading asserting a claim for relief shall state the name, if known to the pleader, of a person meeting the criteria of (1) or (2) of section (a) of this Rule who is not joined and the reason the person is not joined.

(c) Effect of Inability to Join. If a person meeting the criteria of (1) or (2) of section (a) of this Rule cannot be made a party, the court shall determine whether the action should proceed among the parties before it or whether the action should be dismissed. Factors to be considered by the court include: to what extent a judgment rendered in the person's absence might be prejudicial to that person or those already parties; to what extent the prejudice can be lessened or avoided by protective provisions in the judgment or other measures; whether a judgment rendered in the person's absence will be adequate; and finally, whether the plaintiff will have an adequate remedy if the action is dismissed for nonjoinder.

Source: This Rule is derived as follows:

Section (a) is derived from the 1966 version of Fed. R. Civ. P. 19 (a).

Section (b) is derived from the 1966 version of Fed. R. Civ. P. 19 (c).

Section (c) is derived from the 1966 version of Fed. R. Civ. P. 19 (b).