Misjoinder of parties is not ground for dismissal of an action. Parties may be dropped or added by order of the court on motion of any party or of its own initiative at any stage of the action and on such terms as are just. Any claim against a party may be severed and proceeded with separately.
Rule 21.Misjoinder and Nonjoinder of Parties
Current through June 1, 2026 · Last verified July 10, 2026
In one sentenceRule 21 makes clear that joining the wrong parties or leaving someone out is never a reason to dismiss a lawsuit, and lets the court add, drop, or sever parties and claims on its own initiative or on any party's motion at any point in the case.
Full Text of Rule 21
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 21 protects a lawsuit from being thrown out over a mistake in who is named as a party. Misjoinder — bringing in a party who should not be there — and nonjoinder — leaving out someone who should be — are never, by themselves, grounds for dismissal. Instead, the court can add or drop parties by its own order, on a motion from any party, at any stage of the case, and on whatever terms are just under the circumstances.
The rule also lets the court sever a claim against a particular party and let it proceed as its own separate action. That option gives a judge a way to keep a case moving when one claim or one party is causing delay, without dismissing everything else in the lawsuit.
Frequently Asked Questions
Can my case be dismissed because I sued the wrong party by mistake?
No. Rule 21 states that misjoinder of parties is not a ground for dismissal; the court instead adds or drops parties as needed.
Can a court add a party to my lawsuit without me asking?
Yes. Rule 21 lets the court add or drop parties on its own initiative, not only on a motion from one of the parties.
What happens if I forgot to name someone who should have been a party?
The court can order that person joined at any stage of the case under Rule 21, rather than dismissing the action for nonjoinder.
Can a judge split off one claim against one defendant to be handled separately?
Yes. Rule 21 allows the court to sever any claim against a party and have it proceed separately from the rest of the case.
Source & verification. The rule text is reproduced verbatim from the
official Colorado Rules of Civil Procedure (Colo. R. Civ. P. 21). 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
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