Short answer. Yes. Rule 6, Section 5 lists another action pending between the same parties for the same cause as an affirmative defense, and an affirmative defense is raised directly in the answer. You do not need a separate motion — you plead the pending case as part of your answer to the complaint.
What the law says
Affirmative defenses may also include grounds for the dismissal of a complaint, specifically, that the court has no jurisdiction over the subject matter, that there is another action pending between the same parties for the same cause, or that the action is barred by a prior judgment.
Rule 6, Section 5 — Defenses. Read the full provision →
Where this defense fits in the answer
Rule 6, Section 5 divides defenses into two kinds. A negative defense is a specific denial of a fact the plaintiff alleges. An affirmative defense is different — it is new matter that, even if everything the plaintiff says is assumed true, would still bar recovery. The rule expressly lists three dismissal-type grounds as affirmative defenses: lack of jurisdiction over the subject matter, another action pending between the same parties for the same cause, and a bar by prior judgment. Because these are affirmative defenses, they belong in the answer itself, not in a separate pleading filed before it.
What 'another action pending for the same cause' means
The ground applies when there is already a case, between the same parties, over the same cause of action, that has not yet been resolved. The concern is straightforward: allowing both cases to proceed risks two courts reaching different, possibly conflicting, judgments on the identical dispute, and forces the defendant to answer for the same claim twice at the same time. Raising it in the answer puts the fact of the other pending case before the court early, alongside your other defenses, rather than waiting to see how the first case turns out.
It sits alongside the classic contract-type defenses
The same list of affirmative defenses names fraud, statute of limitations, release, payment, illegality, statute of frauds, estoppel, former recovery, and discharge in bankruptcy, among others, as well as any other matter by way of confession and avoidance. A pending prior action for the same cause sits in that same category — it does not deny the underlying facts the plaintiff alleges, it introduces a separate fact that, if proven, defeats the claim regardless. Treating it as an affirmative defense rather than a bare denial keeps the burden of proving it on the party raising it.
Why raising it early matters
Because this ground is pleaded as part of the answer, it is before the court from the start of the case rather than surfacing later as a surprise. A defendant who has genuinely already been sued once over the same claim, in a case still pending, has a real interest in getting that fact on record early — it affects how the second case should be handled and avoids the waste of litigating the identical dispute twice in parallel before either court reaches a final judgment.