Federal counterclaims: the one you must plead, the one you may, and the crossclaim in between
Federal procedure · Last verified August 17, 2026
Rule 13 is short and its consequences are permanent. A claim that arises out of the same transaction as the one against you is compulsory: if you had it when you served your pleading and you did not plead it, you cannot bring it later.
Everything else is optional, and unusually free — a permissive counterclaim need have nothing to do with the case at all.
The compulsory counterclaim
Rule 13(a)(1):
A pleading must state as a counterclaim any claim that — at the time of its service — the pleader has against an opposing party if the claim: (A) arises out of the transaction or occurrence that is the subject matter of the opposing party's claim; and (B) does not require adding another party over whom the court cannot acquire jurisdiction.
Three elements, and the timing element does real work.
"At the time of its service." The measurement point is service of your pleading, not the filing of the complaint and not the close of pleadings. A claim you did not yet have is not caught.
Same transaction or occurrence. The same test Rule 14 uses for impleader and Rule 13(g) for crossclaims.
And condition (B) is a saving provision. If pleading the counterclaim would require adding someone the court cannot reach, the claim is not compulsory. That protects a defendant from being forced to forfeit a claim it had no way to bring here.
Rule 13(a)(2) — two exceptions. The pleader need not state the claim if:
(A) when the action was commenced, the claim was the subject of another pending action; or (B) the opposing party sued on its claim by attachment or other process that did not establish personal jurisdiction over the pleader on that claim, and the pleader does not assert any counterclaim under this rule.
Exception (B) is conditional on your own restraint: it protects a party haled in by quasi-in-rem process only so long as that party asserts no counterclaim. Assert one and the protection goes.
The consequence of omission is not stated in Rule 13 itself — the rule says only that the pleading "must" include it. The preclusive effect comes from case law, and it is why the rule matters.
The permissive counterclaim
Rule 13(b): "A pleading may state as a counterclaim against an opposing party any claim that is not compulsory."
Any claim. There is no relatedness requirement at all — an unrelated debt, a different contract, a claim from years before. California's CCP 428.10(a) takes the same approach for claims against the party who sued you.
The practical constraint is jurisdictional rather than procedural: a permissive counterclaim needs its own basis for subject-matter jurisdiction, since it does not arise from the same transaction and so does not draw on supplemental jurisdiction the way a compulsory counterclaim does.
What a counterclaim may ask for
Rule 13(c):
A counterclaim need not diminish or defeat the recovery sought by the opposing party. It may request relief that exceeds in amount or differs in kind from the relief sought by the opposing party.
So a defendant sued for $50,000 may counterclaim for $5 million, or for an injunction. The counterclaim is not a set-off device; it is an independent claim that happens to be pleaded in the same document.
Counterclaims acquired later
Rule 13(e):
The court may permit a party to file a supplemental pleading asserting a counterclaim that matured or was acquired by the party after serving an earlier pleading.
This is the safety valve for the Rule 13(a)(1) timing rule. A claim that did not exist when you served your answer was never compulsory — and Rule 13(e) is how you bring it in when it arises. Note it requires the court's permission, on a supplemental pleading under Rule 15(d).
Against the United States — Rule 13(d): the rules "do not expand the right to assert a counterclaim — or to claim a credit — against the United States or a United States officer or agency." Sovereign immunity governs, and Rule 13 does not disturb it.
Crossclaims against a co-party
Rule 13(g):
A pleading may state as a crossclaim any claim by one party against a coparty if the claim arises out of the transaction or occurrence that is the subject matter of the original action or of a counterclaim, or if the claim relates to any property that is the subject matter of the original action. The crossclaim may include a claim that the coparty is or may be liable to the crossclaimant for all or part of a claim asserted in the action against the crossclaimant.
Three points.
Crossclaims are always permissive. The rule says "may," and there is no compulsory crossclaim in federal practice. A co-defendant's claim against another co-defendant is not lost by being left out.
The relatedness test is broader than Rule 13(a)'s. It reaches the transaction of the original action or of a counterclaim, and separately reaches claims relating to property that is the subject matter of the action.
And it expressly covers indemnity and contribution — "is or may be liable to the crossclaimant for all or part of a claim asserted in the action." That is the same derivative structure Rule 14 uses for third parties, available here against someone already in the case.
Adding parties — Rule 13(h): "Rules 19 and 20 govern the addition of a person as a party to a counterclaim or crossclaim." The guide on adding parties in federal court covers those.
Separate trials and separate judgments
Rule 13(i):
If the court orders separate trials under Rule 42(b), it may enter judgment on a counterclaim or crossclaim under Rule 54(b) when it has jurisdiction to do so, even if the opposing party's claims have been dismissed or otherwise resolved.
A counterclaim can therefore outlive the claim that prompted it, and can be reduced to an appealable judgment under Rule 54(b) while the rest of the case continues or after it ends.
Where the deadlines come from
Rule 13 sets no deadline of its own — the counterclaim goes in the pleading, so the timing comes from Rule 12(a):
| Pleading | Deadline |
|---|---|
| Answer to a complaint | 21 days after service, or 60 / 90 with waiver under Rule 4(d) |
| Answer to a counterclaim or crossclaim | 21 days after being served with it |
| Reply to an answer | 21 days after being served with an order to reply |
| Counterclaim acquired later | by supplemental pleading with leave — Rule 13(e) |
And if you miss a compulsory counterclaim in the answer, the routes back are an amendment under Rule 15 — as of course within the Rule 15(a)(1) window, otherwise by leave — or Rule 13(e) if the claim matured afterwards.
Deciding what to plead
| The claim | Rule | Must you plead it? |
|---|---|---|
| Against the party suing you, same transaction, no unreachable party needed | 13(a) | Yes — or lose it |
| Same transaction, but requires a party the court cannot reach | 13(a)(1)(B) | No |
| Already the subject of another pending action | 13(a)(2)(A) | No |
| You were haled in by attachment without personal jurisdiction | 13(a)(2)(B) | No — but only if you counterclaim on nothing |
| Against the party suing you, unrelated | 13(b) | No — permissive, needs its own jurisdictional basis |
| Against a co-party, same transaction or the same property | 13(g) | No — always permissive |
| Indemnity or contribution from a co-party | 13(g) | No |
| Indemnity or contribution from a non-party | Rule 14 | No — 14 days to implead without leave |
| Matured after you pleaded | 13(e) | No — supplemental pleading, with leave |
How the federal rule compares
| Federal | California | Washington | Oregon | |
|---|---|---|---|---|
| Compulsory counterclaim | Rule 13(a) | CCP 426.30 | CR 13(a) | ORCP 22 A |
| Measured at | service of the pleading | service of the answer | pleading | pleading |
| Unrelated claim against the plaintiff | permitted — 13(b) | permitted — CCP 428.10(a) | permitted | permitted |
| Relief may exceed the claim | express — 13(c) | — | — | — |
| Relief for an omitted compulsory claim | Rule 15 amendment | CCP 426.50 — mandatory on good faith, any time | leave to amend | leave to amend |
| Crossclaims compulsory | no | no | no | no |
| Later-acquired counterclaim | 13(e), with leave | CCP 428.50(c) | CR 13(e) | ORCP 22 |
California is the notable contrast on relief from omission: CCP 426.50 makes leave mandatory where the party acted in good faith, and directs that the subdivision "be liberally construed to avoid forfeiture of causes of action." Federal practice has no equivalent safety net, which makes the initial catalogue more important.
A short checklist
- Before you answer, list every claim you have against the plaintiff. That list, as it stands on the day you serve, is what Rule 13(a) measures.
- Ask whether each arises from the same transaction or occurrence. Those are compulsory.
- Check condition (B). If pleading it would require a party the court cannot reach, it is not compulsory — but say so rather than assuming.
- Consider the permissive ones too. Rule 13(b) lets you bring anything against the opposing party, subject to finding independent jurisdiction.
- Do not limit the counterclaim to the amount sued for. Rule 13(c) is explicit.
- For co-parties, use Rule 13(g) — including for indemnity and contribution — and remember it is never compulsory.
- For non-parties, use Rule 14, and diary the 14 days from serving your answer.
- If a claim matures later, move under Rule 13(e) for leave to file a supplemental pleading.
- If you left a compulsory claim out, amend immediately — as of course under Rule 15(a)(1) if you still can, by leave if not.
Where these rules live
- FRCP 12 — Defenses and objections
- FRCP 13 — Counterclaim and crossclaim
- FRCP 14 — Third-party practice
- FRCP 15 — Amended and supplemental pleadings
- FRCP 19 — Required joinder of parties
- FRCP 20 — Permissive joinder of parties
- FRCP 42 — Consolidation; separate trials
- FRCP 54 — Judgment; costs
This page explains what the rules say. It isn't legal advice, and the preclusive effect of failing to plead a compulsory counterclaim, together with the supplemental jurisdiction analysis, comes from case law and statute this site doesn't cover.