(a) Persons to be Joined if Feasible. A person who is properly subject to service of process in the action shall be joined as a party in the action if: (1) In his absence complete relief cannot be accorded among those already parties, or (2) he claims an interest relating to the subject of the action and is so situated that the disposition of the action in his absence may: (A) As a practical matter impair or impede his ability to protect that interest or (B) leave any of the persons already parties subject to a substantial risk of incurring double, multiple, or otherwise inconsistent obligations by reason of his claimed interest. If he has not been so joined, the court shall order that he be made a party. If he should join as a plaintiff but refuses to do so, he may be made a defendant, or, in a proper case, an involuntary plaintiff. If the joined party objects to venue and his joinder would render the venue of the action improper, he shall be dismissed from the action.
Rule 19.Joinder of Persons Needed for Just Adjudication
Current through June 1, 2026 · Last verified July 10, 2026
In one sentenceRule 19 requires courts to bring in any person whose absence would prevent complete relief or put that person's or existing parties' interests at risk, and tells courts how to decide whether to proceed or dismiss when such a person cannot be joined.
Full Text of Rule 19
(b) Determination by Court Whenever Joinder Not Feasible. If a person as described in subsections (a)(1) and (a)(2) of this Rule cannot be made a party, the court shall determine whether in the interest of justice the action should proceed among the parties before it, or should be dismissed, the absent person being thus regarded as indispensable. The factors to be considered by the court include: First, to what extent a judgment rendered in the person's absence might be prejudicial to him or those already parties; second, the extent to which, by protective provisions in the judgment, by the shaping of relief, or other measures, the prejudice can be lessened or avoided; third, whether a judgment rendered in the person's absence will be adequate; fourth, whether the plaintiff will have an adequate remedy if the action is dismissed for nonjoinder.
(c) Pleading Reasons for Nonjoinder. A pleading asserting a claim for relief shall state the names, if known to the pleader, of any persons as described in subsections (a)(1) and (a)(2) of this Rule who are not joined, and the reasons why they are not joined.
Amendment History
The source reproduced here (current through June 1, 2026) records no amendment to this rule since its original adoption — no Credits line appears for it in the compiled rules. For the underlying adopting order and any later amendments, see the Colorado General Assembly.
Plain-English Summary
Rule 19 identifies people who need to be part of a lawsuit before it can go forward. A person who can be served with process must be joined if leaving them out would prevent the court from giving complete relief to those already in the case, or if that person has a claimed interest in the dispute that proceeding without them could impair, or that could expose an existing party to double or inconsistent obligations. If someone who belongs on the plaintiff's side refuses to join voluntarily, the court can name them as a defendant, or, in some cases, an involuntary plaintiff.
When a necessary person cannot be brought into the case, Rule 19(b) tells the court how to decide whether the case should proceed without that person or be dismissed. The court weighs the prejudice to the absent person and existing parties, whether that prejudice can be reduced by shaping the judgment, whether a judgment issued without the absent person would still mean something, and whether the plaintiff would have anywhere else to go if the case were dismissed. Rule 19(c) also requires a plaintiff who leaves out a known necessary person to explain in the pleading why.
Frequently Asked Questions
What happens if joining a necessary party would ruin venue?
Rule 19(a) requires the court to dismiss that party from the action when the person objects to venue and their joinder would make venue improper.
Can a court force someone to join a lawsuit as a plaintiff?
Not directly — Rule 19(a) instead lets the court name a person who should be a plaintiff but refuses to join as a defendant, or in a proper case, an involuntary plaintiff.
What does it mean to call an absent person indispensable?
It means the court has decided under Rule 19(b) that the case cannot go forward without that person, so the action must be dismissed rather than continue in their absence.
Do I have to tell the court if I left someone out of my lawsuit?
Yes. Rule 19(c) requires a pleading to name any known person who should have been joined under Rule 19(a) and explain why they were not.
Source & verification. The rule text is reproduced verbatim from the
official Colorado Rules of Civil Procedure (Colo. R. Civ. P. 19). Prescribed by the Supreme Court of Colorado (C.R.S. § 13-2-108; Colo. Const. art. VI). The plain-English summary is original and written by us. Last verified July 10, 2026. ·
Official source
Also known as: necessary partyindispensable partyjoinder required coloradowho must be joined in a lawsuitCRCP 19involuntary plaintiff