Short answer. It depends on how the amendment was made. If the plaintiff amended as a matter of right, you have thirty calendar days from service of the amended complaint. If the amendment needed leave of court, you have fifteen calendar days from notice of the order admitting it. An earlier answer may stand if no new one is filed.
What the law says
the plaintiff files an amended complaint as a matter of right, the defendant shall answer the same within thirty calendar days after being served with a copy thereof
Rule 11, Section 3 — Answer to amended complaint. Read the full provision →
What the law says
Where its filing is not a matter of right, the defendant shall answer the amended complaint within fifteen calendar days from notice of the order admitting the same.
Rule 11, Section 3 — Answer to amended complaint. Read the full provision →
What the law says
An answer earlier filed may serve as the answer to the amended complaint if no new answer is filed.
Rule 11, Section 3 — Answer to amended complaint. Read the full provision →
Thirty days when amendment was a matter of right
Where the plaintiff files an amended complaint as a matter of right, the defendant shall answer the same within thirty calendar days after being served with a copy thereof. An amendment as a matter of right is one the plaintiff could make without asking the court's permission, which the Rules allow early in the case before a responsive pleading is served. In that situation you get a full thirty calendar days — the same period allowed for an original complaint — counted from the day the amended complaint is actually served on you.
Fifteen days when leave of court was needed
The period is halved when the court had to allow the amendment: Where its filing is not a matter of right, the defendant shall answer the amended complaint within fifteen calendar days from notice of the order admitting the same. Two details matter. The count runs from notice of the order admitting the amended complaint, not from service of the pleading itself — you may have received the proposed amendment weeks earlier, attached to the motion for leave. And it is fifteen days, on the logic that you have already seen both the case and the proposed changes.
Your earlier answer can carry over
The rule supplies a safety net: An answer earlier filed may serve as the answer to the amended complaint if no new answer is filed. Failing to file a fresh answer therefore does not automatically put you in default if your original answer is on record — it simply becomes the operative response. But the net has holes. If the amendment adds new claims, new parties, or new allegations your old answer never addressed, standing on it leaves those matters unmet. Read the amendments line by line against your answer before deciding to rely on this provision.
The same periods reach other amended pleadings
The section closes by extending itself: the rule applies to the answer to an amended counterclaim, an amended cross-claim, an amended third-party complaint, and an amended complaint-in-intervention. Whatever amended pleading requires a response from you, the same two-track computation governs — thirty calendar days from service if the amendment was of right, fifteen from notice of the admitting order if it needed leave. The first thing to establish, always, is which track the amendment travelled, because that single fact fixes your deadline.