(a) When Defendant May Bring in Third Party. At any time after commencement of the action a defending party, as a third-party plaintiff, may cause a summons and complaint to be served upon a person not a party to the action who is or may be liable to him for all or part of the plaintiff's claim against him. The third-party plaintiff need not obtain leave to make the service if he files the third-party complaint not later than 14 days after he serves his original answer. Otherwise he must obtain leave on motion upon notice to all parties to the action. The person served with the summons and third-party complaint, hereinafter called the third-party defendant, shall make his defenses to the third party plaintiff's claim as provided in Rule 12 and his counterclaim against the third-party plaintiff and cross claims against other third-party defendants as provided in Rule 13. The third-party defendant may assert against the plaintiff any defenses which the third-party plaintiff has to the plaintiff's claim. The third-party defendant may also assert any claim against the plaintiff arising out of the transaction or occurrence that is the subject matter of the plaintiff's claim against the third-party plaintiff. The plaintiff may assert any claim against the third-party defendant arising out of the transaction or occurrence that is the subject matter of the plaintiff's claim against the third-party plaintiff, and the third-party defendant thereupon shall assert his defenses as provided in Rule 12 and his counterclaim and cross claims as provided in Rule 13. Any party may move to strike the third-party claim, or for its severance or separate trial. A third-party defendant may proceed under this Rule against any person not a party to the action who is or may be liable to him for all or part of the claim made in the action against the third-party defendant.
Rule 14.Third-Party Practice
Current through June 1, 2026 · Last verified July 10, 2026
In one sentenceRule 14 lets a defending party bring a new person into the lawsuit as a third-party defendant when that person may owe reimbursement or contribution for the plaintiff's claim, and lets a plaintiff do the same once a counterclaim is filed against it.
Full Text of Rule 14
(b) When Plaintiff May Bring in Third Party. When a counterclaim is asserted against a plaintiff, he may cause a third party to be brought in under circumstances which under this Rule would entitle a defendant to do so.
Amendment History
Amended effective January 1, 2012.
Plain-English Summary
Rule 14 covers impleader — the process of adding someone to a pending lawsuit who might end up owing money to a party already in the case. A defendant who thinks another person shares responsibility for the plaintiff's claim can serve that person with a third-party summons and complaint, turning them into a third-party defendant. If the defendant does this within 14 days of serving its own answer, no court permission is needed; after that window closes, the defendant must ask the court for leave and give notice to the other parties.
Once brought in, the third-party defendant answers under Rule 12 and can raise counterclaims or cross-claims under Rule 13. The new party can also raise any defense the third-party plaintiff had against the original claim, and can bring its own claim against the plaintiff if it arises from the same transaction or occurrence. The plaintiff, in turn, may assert a claim directly against the third-party defendant on that same basis. Any party can ask the court to strike, sever, or separately try the third-party claim, and a third-party defendant facing exposure can repeat the process against yet another person.
The rule works the other direction too: if a plaintiff faces a counterclaim, it can bring in a third party under the same procedure a defendant would use.
Frequently Asked Questions
What is a third-party complaint under Colorado Rule 14?
A third-party complaint is how a defendant pulls another person into an existing lawsuit, claiming that person owes all or part of what the defendant might have to pay the plaintiff.
How long does a defendant have to file a third-party complaint without asking the court first?
A defendant can serve a third-party complaint without leave of court up to 14 days after serving its original answer; after that, it needs court permission and must notify the other parties.
Can a plaintiff use Rule 14 to bring in a third party?
Yes — if a defendant files a counterclaim against the plaintiff, the plaintiff can bring in a third party under the same procedure available to defendants.
Can the third-party defendant bring in someone else?
Yes, a third-party defendant who believes another person shares responsibility for the claim against it may proceed under Rule 14 to bring that person into the case as well.
Source & verification. The rule text is reproduced verbatim from the
official Colorado Rules of Civil Procedure (Colo. R. Civ. P. 14). 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: impleaderthird party complaintbringing in a third-party defendantcontribution claim colorado civil caseCRCP 14adding a party who owes reimbursementthird-party practice rule