Third-Party Complaint: Bringing in a New Defendant Under FRCP 14

A third-party complaint is a pleading filed by a defendant (the third-party plaintiff) bringing a new party (the third-party defendant) into the case to assert claims for indemnification, contribution, or other derivative liability. Authorized in federal court by Federal Rule of Civil Procedure 14, the third-party complaint allows a defendant to shift or share liability without filing a separate lawsuit. The new claim must be derivative of the underlying claim ("if I am liable to the plaintiff, then this third party is liable to me").

This article unpacks the FRCP 14 standard, the timing rules, the difference between a third-party complaint and a counterclaim or cross-claim, the strategic uses, and the procedural mechanics. Read it beside the counterclaim guide, the counterclaim vs. crossclaim overview, and the amended complaint guide.

FRCP 14 Standard

Rule 14(a) provides: a defending party may, as third-party plaintiff, serve a summons and complaint on a non-party who is or may be liable to it for all or part of the claim against it. The third-party claim must be derivative; the third party's liability depends on the third-party plaintiff being liable to the plaintiff first.

Common derivative theories:

• Indemnification (contractual or common law).
• Contribution from joint tortfeasors.
• Subrogation in insurance contexts.
• Implied indemnification based on the parties' relationship.

The derivative-liability requirement is the most common ground for striking a third-party complaint. Rule 14 does not permit an alternative-liability theory: a defendant cannot implead someone merely to argue that the absent party, not the defendant, injured the plaintiff. That argument is a defense to the plaintiff's case, not a third-party claim. Courts routinely dismiss third-party complaints that simply point the finger at another possible wrongdoer without an indemnification, contribution, or similar pass-through theory connecting the third party's liability to the defendant's own.

Timing

The defending party may file a third-party complaint within 14 days after serving its original answer. After 14 days, leave of court is required, granted on a discretionary good-cause analysis. Courts grant leave readily early in the case and become increasingly reluctant as discovery progresses, particularly when the third-party complaint would delay the trial or burden discovery.

Third-Party Complaint vs. Other Claim Types

Claim type	Filed by	Filed against	Subject matter
Counterclaim	Defendant	Plaintiff	Same or different transaction
Cross-claim	Co-defendant	Co-defendant	Same transaction or property
Third-party complaint	Defendant (third-party plaintiff)	Non-party (new defendant)	Derivative liability for the underlying claim

The key feature of a third-party complaint is that it brings a new party into the existing case. Counterclaims and cross-claims involve only existing parties.

Examples

Examples of third-party claims include:

• A car accident defendant who claims a third party caused the accident, seeking contribution.
• A general contractor sued for construction defects who brings in a subcontractor on indemnification.
• A retailer sued for product liability who brings in the manufacturer on common-law indemnification.
• An insurer sued for bad faith who brings in the insured's broker on negligence.
• An employer sued for vicarious liability who brings in the employee on contractual indemnification.

Procedural Mechanics

To bring in a third-party defendant under Rule 14, the third-party plaintiff must:

1. File the third-party complaint within 14 days after serving the original answer (or with leave of court).
2. Issue a summons (yes, a summons is required).
3. Serve the summons and third-party complaint on the third-party defendant under Rule 4.
4. Provide notice to the original parties.

The third-party defendant must answer within the time fixed by Rule 12. Once joined, the third-party defendant has the rights of any defendant: file motions to dismiss, raise affirmative defenses, demand jury trial, and conduct discovery.

Third-Party Defendant's Options

Once served, the third-party defendant may:

• File an answer to the third-party complaint with affirmative defenses.
• File a motion to dismiss the third-party complaint under Rule 12(b).
• Assert any defenses the third-party plaintiff has against the original plaintiff (Rule 14(a)(2)(C)).
• Assert a counterclaim against the third-party plaintiff.
• Assert a cross-claim against another third-party defendant.
• Assert a claim directly against the original plaintiff if it arises out of the same transaction or occurrence (Rule 14(a)(2)(D)).
• File its own third-party complaint against a fourth party.

Statute of Limitations Considerations

A defendant seeking to enforce non-contractual rights, such as statutory contribution or common-law indemnification, must commence a third-party complaint within the applicable statute of limitations for the underlying claim. In some jurisdictions, the statute of limitations on indemnification or contribution claims does not begin to run until the underlying judgment is entered or paid.

Practitioners should research the relevant state's accrual rules carefully; the federal rule (Rule 14) is procedural, but the substantive limitations period is determined by state law.

Strategic Considerations

Third-party practice has tactical advantages:

• Single trial: all liability issues resolved in one proceeding.
• Cost savings: discovery and trial expenses spread across multiple parties.
• Pressure: settlement dynamics improve when all potentially liable parties are at the table.
• Joint and several considerations: contribution and indemnification claims protected against later relitigation.

Disadvantages include:

• Trial complexity increases with each added party.
• Discovery scope expands.
• Settlement negotiations become more complicated.
• Judicial reluctance to permit late additions.

Severance and Trial Issues

Under Rule 14(a)(4), the original plaintiff or the third-party plaintiff may move to strike the third-party claim, sever it for separate trial, or sever it for separate proceedings. Severance is granted when the third-party claim threatens to confuse the jury or unduly delay trial. The court has broad discretion.

When You Need an Attorney

Third-party practice is technical and the timing rules are unforgiving. Legal Tank's attorney-drafted third-party complaint service handles the pleading, summons, derivative liability analysis, and motion for leave when the 14-day window has passed. The third-party complaint template is available at no cost for unrepresented parties. For related claim types, see the counterclaim vs. crossclaim guide.

Frequently Asked Questions

What does a third party complaint mean?

A third-party complaint is a legal document filed by a defendant (the third-party plaintiff) against a non-party (the third-party defendant), alleging that the third party is responsible for some or all of the damages claimed by the original plaintiff against the defendant. The claim must be derivative of the underlying claim, that is, the third-party defendant's liability depends on the third-party plaintiff being liable to the original plaintiff first. Common theories include indemnification, contribution, and subrogation.

How long do you have to file a third party complaint?

Under Federal Rule of Civil Procedure 14(a), the defending party may file a third-party complaint within 14 days after serving its original answer. After 14 days, leave of court is required, granted on a discretionary good-cause analysis. A defendant seeking to enforce non-contractual rights, such as statutory contribution or common-law indemnification, must also commence a third-party complaint within the applicable statute of limitations for the underlying claim under state law.

What is an example of a third party claim?

Examples of third-party claims include a car accident defendant who claims a third party caused the accident and seeks contribution, a general contractor sued for construction defects who brings in a subcontractor for indemnification, a retailer sued for product liability who brings in the manufacturer, and an insurer sued for bad faith who brings in the broker. Each rests on a derivative-liability theory: if the original defendant is liable to the plaintiff, then the third party is liable to the original defendant.

Do you need a summons for a third party complaint?

Yes. Under Rule 14(a), when a defending party brings in a third party, the third-party plaintiff must serve a summons and complaint on the third-party defendant under Rule 4. The third-party defendant is treated as any other defendant for service purposes; a summons is required to give notice and to invoke the court's personal jurisdiction. Failure to issue and serve a proper summons can result in dismissal of the third-party complaint for insufficient service.

What is the difference between contribution and indemnification?

Contribution shifts part of a loss: joint tortfeasors share responsibility, so a defendant who pays the plaintiff can recover each co-wrongdoer's proportionate (in some states pro rata) share. Indemnification shifts the entire loss to another party, whether by an express contract clause, by a contract implied from the parties' relationship, or by equitable principles where the defendant's liability is purely vicarious or passive. The distinction is substantive state law; Rule 14 supplies only the procedural vehicle for asserting either theory in the pending case, and the elements vary by jurisdiction.

Does a third-party complaint need its own basis for federal jurisdiction?

Usually not. A Rule 14 claim for indemnification or contribution is so related to the underlying action that it falls within supplemental jurisdiction under 28 U.S.C. § 1367, even when the third-party defendant would destroy complete diversity. One caveat: in diversity cases, § 1367(b) bars the original plaintiff from asserting claims against a non-diverse third-party defendant, so a plaintiff cannot use the defendant's impleader to reach a party it could not have sued directly. Personal jurisdiction and proper service over the third-party defendant are still required. For how the underlying case gets into federal court at all, see the subject matter jurisdiction guide.

Can the plaintiff assert claims against the third-party defendant?

Yes. Under Rule 14(a)(3), once a third-party defendant is joined, the original plaintiff may assert any claim against it that arises out of the same transaction or occurrence as the plaintiff's claim against the original defendant. The third-party defendant must then respond under Rule 12 and may raise counterclaims and cross-claims of its own. In diversity cases this option is limited by 28 U.S.C. § 1367(b) when the plaintiff and the third-party defendant are citizens of the same state.