Group IV: Parties · Last amended March 1, 2017 · Last verified July 14, 2026
In one sentenceRule 19 tells a court when an absent person must be brought into a lawsuit because complete relief is impossible without them or their absence would harm someone's interests, and what to do when that person cannot be joined.
(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.
(b)When Joinder Is Not Feasible. — If a person who is required to be joined if feasible cannot be joined, the court must determine whether, in equity and good conscience, the action should proceed among the existing parties or should be dismissed. The factors for the court to consider include:
(1)the extent to which a judgment rendered in the person’s absence might prejudice that person or the existing parties;
(2)the extent to which any prejudice could be lessened or avoided by:
(A)protective provisions in the judgment;
(B)shaping the relief; or
(C)other measures;
(3)whether a judgment rendered in the person’s absence would be adequate; and
(4)whether the plaintiff would have an adequate remedy if the action were dismissed for nonjoinder.
(c)Pleading the Reasons for Nonjoinder. — When asserting a claim for relief, a party must state:
(1)the name, if known, of any person who is required to be joined if feasible but is not joined; and
(2)the reasons for not joining that person.
(d)Exception for Class Actions. — This rule is subject to Rule 23.
Amendment History
Added February 2, 2017, effective March 1, 2017.
Plain-English Summary
Rule 19 addresses lawsuits that cannot be resolved in full without someone who isn't currently a party. A person must be joined, if joinder is possible, when the court cannot give complete relief among the parties already in the case without that person, or when the absent person has an interest in the dispute that could be practically damaged by a decision made without them, or that could leave an existing party facing double or inconsistent obligations. Once the court identifies a required party, it must order that person joined — as a defendant, or as a plaintiff even over that person's objection if they refuse to join voluntarily. If joining that person would ruin venue, the court must dismiss that party rather than the whole case.
Sometimes the required person cannot be brought in — perhaps the court has no way to reach them. When that happens, Rule 19 asks the court to weigh, in equity and good conscience, whether to proceed without them or dismiss the case entirely. The court looks at how much a judgment made in that person's absence might hurt them or the existing parties, whether protective terms or reshaped relief could ease that harm, whether a judgment without the absent person would mean anything, and whether the plaintiff would still have somewhere else to turn if the case were dismissed.
A party asserting a claim must flag this issue up front: if someone who should be joined is missing, the pleading must name that person, if known, and explain why they aren't part of the case. Class actions are handled separately, since Rule 23 has its own framework for representing absent people.
Frequently Asked Questions
What makes a person a required party under Rule 19?
A person must be joined if the court cannot grant complete relief without them, or if their absence could practically damage their own interest in the dispute, or could leave an existing party facing double or inconsistent obligations.
What happens if a required party cannot be joined? Is the case automatically dismissed?
Not automatically. The court weighs, in equity and good conscience, factors including potential prejudice, whether that prejudice can be reduced, whether a judgment without the person would mean anything, and whether the plaintiff has another remedy — then decides whether to proceed or dismiss.
Can a required party be added as a plaintiff against their will?
Yes. Someone who should be a plaintiff but refuses to join voluntarily can instead be made a defendant or, in the right case, an involuntary plaintiff.
What if joining the required party would ruin venue?
If a joined party objects to venue and joining them would make venue improper, the court must dismiss that party rather than dismiss the whole case.
Do I have to explain in my complaint why I did not name a required party?
Yes. If a person who should be joined is missing, the pleading must name that person, if known, and state the reasons they were not joined.
Source & verification. Rule text and amendment history are
reproduced verbatim from the Wyoming Rules of Civil Procedure, adopted by the
Supreme Court of Wyoming. Last verified July 14, 2026. ·
Official source
Also known as:necessary party ruleindispensable party wyomingrequired joinder rule 19case dismissed missing partyinvoluntary plaintiff