(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 petition to be served upon a person not a party to the action who is or may be liable to the defending party for all or part of the plaintiff’s claim against the defending party. The third-party plaintiff need not obtain leave to make the service if the third-party petition is filed not later than ten days after the defending party serves the original answer. Otherwise, the defending party shall obtain leave on motion upon notice to all parties to the action. The person served with the summons and third-party petition, hereinafter called the third-party defendant, shall make defenses to the third-party plaintiff’s claim as provided in Rule 55 and counterclaims against the third-party plaintiff and cross-claims against other third-party defendants as provided in Rule 55. The third-party defendant may assert against the plaintiff any defenses that 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 defenses as provided in Rule 55 and counterclaims and cross-claims as provided in Rule 55. 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 52.11 against any person not a party to the action who is or may be liable to the third-party defendant for all or part of the claim made in the action against the third-party defendant.
Rule 52.11.Third-Party Practice.
Part I · Rule 52: Parties · Last amended January 1, 1994 · Last verified July 22, 2026
In one sentenceRule 52.11 lets a defending party bring in a new third-party defendant who may be liable for all or part of the plaintiff's claim, sets when leave of court is required, and defines what claims the plaintiff, the third-party plaintiff, and the third-party defendant may assert against one another.
Full Text of Rule 52.11
(b) When Plaintiff May Bring in Third Party. When a counterclaim is asserted against a plaintiff, the plaintiff may cause a third-party to be brought in under circumstances that under this Rule 52.11 would entitle a defendant to do so.
(c) Execution by Third-Party Plaintiff—Limitation. Where a third-party defendant is liable to the plaintiff, or to any one holding a similar position under Rule 52.11(a) or Rule 52.11(b), on the claim on which a third- party plaintiff has been sued, execution by the third-party plaintiff on a judgment against the third-party defendant shall be permitted only to the extent that the third-party plaintiff has paid any judgment obtained against the third-party plaintiff by the obligee.
Amendment History
Renumbered from 52.10 and amended April 21, 1972, eff. Dec. 1, 1972. Amended Sept. 28, 1993, eff. Jan. 1, 1994.
Official Comment
Paragraph (a) is the same as Rule 14(a) of the Federal Rules of Civil Procedure. Paragraph (b) is the same as prior Rule 52.10(b). Paragraph (c) is the same as prior Rule 52.10(c). Compare: Rule 14 of the Federal Rules of Civil Procedure.
Plain-English Summary
Rule 52.11 lets a defending party — the third-party plaintiff — pull a new party into the case when that new party, the third-party defendant, is or may be liable to the defending party for all or part of the plaintiff's original claim. No leave of court is needed if the third-party petition is filed within ten days after the defending party serves the original answer; after that window, the defending party must seek leave on motion with notice to all parties. Once served, the third-party defendant answers, counterclaims, and cross-claims following Rule 55, and may raise against the plaintiff any defense the third-party plaintiff has to the plaintiff's claim. The third-party defendant may also bring its own claim against the plaintiff arising from the same transaction or occurrence, and the plaintiff, in turn, may assert a claim directly against the third-party defendant arising from that same transaction or occurrence, triggering the same answer, counterclaim, and cross-claim obligations. Any party may move to strike the third-party claim or to have it severed or separately tried, and a third-party defendant facing its own exposure may implead a further party down the chain under this same rule.
Rule 52.11(b) gives a plaintiff the mirror-image right: when a counterclaim is asserted against the plaintiff, the plaintiff may bring in a third party under the same circumstances that would let a defendant do so.
Rule 52.11(c) limits how far a third-party plaintiff can go in collecting on a judgment against the third-party defendant. Where the third-party defendant is liable to the plaintiff, or to anyone in a similar position, on the claim underlying the third-party plaintiff's own liability, the third-party plaintiff may execute on a judgment against the third-party defendant only to the extent the third-party plaintiff has paid the judgment the original obligee obtained. In other words, the third-party plaintiff cannot collect from the third-party defendant faster than it pays the person it owes.
Frequently Asked Questions
What is third-party practice, or impleader, used for under Rule 52.11?
It lets a defending party bring a new party — the third-party defendant — into the existing case when that new party is or may be liable to the defending party for all or part of the plaintiff's claim, avoiding a separate lawsuit over the same underlying facts.
Does a defendant need the court's permission to bring in a third-party defendant?
Not if the third-party petition is filed within ten days after the defending party serves the original answer. After that ten-day window, the defending party must obtain leave of court on motion, with notice to all parties.
Can the third-party defendant raise the original defendant's defenses against the plaintiff?
Yes. Rule 52.11(a) lets the third-party defendant assert against the plaintiff any defenses that the third-party plaintiff has to the plaintiff's claim.
Can the plaintiff sue the third-party defendant directly?
Yes. The plaintiff may assert any claim against the third-party defendant that arises out of the transaction or occurrence underlying the plaintiff's claim against the third-party plaintiff, and the third-party defendant must then answer, counterclaim, or cross-claim as Rule 55 provides.
Can a third-party defendant bring in yet another party?
Yes. Rule 52.11(a) lets a third-party defendant proceed under the same rule against any non-party who is or may be liable to the third-party defendant for all or part of the claim made against it.
When can the third-party plaintiff collect from the third-party defendant?
Only to the extent the third-party plaintiff has already paid the judgment the original obligee obtained. Rule 52.11(c) limits execution on a judgment against the third-party defendant to that amount.
Source & verification. Rule text and amendment history are
reproduced verbatim from the Missouri State & Federal Court Rules, adopted by the
Supreme Court of Missouri. Last verified July 22, 2026. ·
Official source
Also known as: third-party practiceimpleaderthird-party defendantthird-party plaintiffbringing in a third party