Krupski v. Costa Crociere S.P.A., No. 09-337, concerned a personal injury action for injuries plaintiff suffered on a cruise ship. The Court reversed the Eleventh Circuit's affirmance of the district court's dismissal of plaintiff's claims against a newly added defendant, holding that relation back under Fed. R. Civ. P. 15(c)(1)(C) depended on what the party to be added knew or should have known, not on the amending party's knowledge or timeliness in seeking to amend the pleading.
As the Court wrote: "Rule 15(c) of the Federal Rules of Civil Procedure governs when an amended pleading "relates back" to the date of a timely filed original pleading and is thus itself timely even though it was filed outside an applicable statute of limitations. Where an amended pleading changes a party or a party's name, the Rule requires, among other things, that "the party to be brought in by amendment . . . knew or should have known that the action would have been brought against it, but for a mistake concerning the proper party's identity." Rule 1 (c)(1)(C). In this case, the Court of Appeals held that Rule 15(c) was not satisfied because the plaintiff knew or should have known of the proper defendant before filing her original complaint. The court also held that relation back was not appropriate because the plaintiff had unduly delayed in seeking to amend. We hold that relation back under Rule 15(c)(1)(C) depends on what the party to be added knew or should have known, not on the amending party's knowledge or its timeliness in seeking to amend the pleading. Accordingly, we reverse the judgment of the Court of Appeals."