(a) Defendant’s claim against third party. — A defendant, as a third-party plaintiff, may cause a summons and complaint, together with a copy of all pleadings, scheduling notices, court orders, and other papers previously filed in the action, to be served upon a person not a party to the action who is or may be liable to the defendant for all or part of a plaintiff ’s claim against the defendant. A person so served becomes a third-party defendant.
Rule 3-332.Third-party practice
District Court · Last amended July 1, 2011 · Last verified July 13, 2026
In one sentenceA District Court defendant can bring in a third party who may owe the defendant for all or part of the plaintiff's claim, and the rule spells out how that third-party defendant responds and how deadlines work.
Full Text of Rule 3-332
(b) Response by third party. — A third-party defendant shall file a notice of intention to defend pursuant to Rule 3-307 and may assert counterclaims against the third-party plaintiff and cross-claims against other third-party defendants as provided by Rule 3-331. 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.
(c) Plaintiff’s claim against third party. — The plaintiff shall 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 file a notice of intention to defend pursuant to Rule 3-307 and may assert counterclaims and cross-claims as provided by Rule 3-331. If the plaintiff fails to assert any such claim against the third-party defendant, the plaintiff may not thereafter assert that claim in a separate action instituted after the third-party defendant has been impleaded. This section does not apply when a third-party claim has been stricken pursuant to section (e) of this Rule.
(d) Additional parties. — A third-party defendant may proceed under this Rule against any person who is or may be liable to the third-party defendant for all or part of the claim made in the pending action. When a counterclaim is asserted against a plaintiff, the plaintiff may cause a third party to be brought in under circumstances that would entitle a defendant to do so under this Rule.
(e) Time for filing. — A defendant may file a third-party claim at any time before ten days of the scheduled trial date. Within ten days of the scheduled trial date or after trial has commenced, a defendant may file a third-party claim only with the consent of the plaintiff or by order of court.
Amendment History
Amended June 21, 1995, effective Sept. 1, 1995; June 7, 2011, effective July 1, 2011.
Committee Note & Source
Source. This Rule is derived as follows:
Section (a) is derived from former M.D.R. 315 a and b.
Section (b) is derived from former M.D.R. 302 a.
Section (c) is derived from former Rule 315 d.
Section (d) is derived from former Rule 315 f 1 and 2.
Section (e) is derived from former M.D.R. 315 a.
Plain-English Summary
Third-party practice lets a defendant pull someone else into the lawsuit who isn't yet a party but who may be on the hook for all or part of what the plaintiff is claiming against the defendant. The defendant, now also a third-party plaintiff, has a summons and complaint served on that person, along with copies of everything already filed in the case. Once served, that person becomes a third-party defendant with real obligations: they have to file their own notice of intention to defend, and they can assert counterclaims against the defendant who brought them in and cross-claims against other third-party defendants, the same way any party could. They can also raise any defense the original defendant has against the plaintiff, and can bring their own claim against the plaintiff if it arises from the same transaction or occurrence as the plaintiff's claim against the original defendant.
The plaintiff isn't a bystander to this process. If the plaintiff has a claim against the third-party defendant arising from that same transaction or occurrence, the plaintiff has to raise it in the pending case — the third-party defendant then files a notice of intention to defend and can counterclaim or cross-claim just as before. Sitting on that claim carries a real cost: a plaintiff who doesn't raise it here can't bring it later in a separate lawsuit once the third-party defendant has been impleaded. That consequence doesn't apply if the third-party claim itself was struck as untimely.
Third-party practice can go another layer deep. A third-party defendant can implead someone else who may owe them for the claim, using the same procedure. And if a counterclaim is filed against the plaintiff, the plaintiff can bring in a third party too, on the same footing as a defendant could. The one hard limit is timing: a defendant has to file a third-party claim before the 10 days leading up to trial. Inside that final 10-day window, or after trial has already started, a third-party claim needs either the plaintiff's consent or a court order.
Frequently Asked Questions
What is third-party practice?
It lets a defendant bring a new party into the case — a third-party defendant — who may be liable to the defendant for all or part of what the plaintiff is claiming. It keeps related liability disputes in one lawsuit instead of a separate one.
What does a third-party defendant have to do once served?
File a notice of intention to defend. From there, the third-party defendant can assert counterclaims against the party who brought them in, cross-claims against other third-party defendants, defenses the original defendant has against the plaintiff, and related claims of their own against the plaintiff.
Does the plaintiff have to do anything about the third-party defendant?
If the plaintiff has a claim against the third-party defendant arising from the same transaction or occurrence, the plaintiff has to raise it in the pending case. Failing to do so generally blocks the plaintiff from suing on that claim later in a separate action.
Can a third-party defendant bring in yet another party?
Yes. A third-party defendant can implead someone else who may be liable to them for the claim, using the same procedure a defendant would use.
Is there a deadline to file a third-party claim?
A defendant has to file it before the 10 days leading up to the scheduled trial date. Within that final window, or after trial has started, filing needs either the plaintiff's consent or a court order.
Source & verification. Rule text, Committee Note, Source note, and
amendment history are reproduced verbatim from the Maryland Rules, adopted by the
Supreme Court of Maryland. Last verified July 13, 2026. ·
Official source
Also known as: third-party complaint district court marylandimpleader district courtthird-party defendant district courtbringing in a third party lawsuit district courtthird-party practice deadline district court