United States Supreme Court Unanimously Holds That an Amended Complaint Can Deprive Federal Courts of Jurisdiction

By V.R. Bohman and Cameron J. Schlagel

The Supreme Court ruled on January 15, 2025, that if a plaintiff amends a complaint to remove federal claims after a case has been removed to federal court, the federal court loses its jurisdiction over the remaining state-law claims and must remand the case back to state court. The decision resolved a split among lower courts and affirmed the Eighth Circuit’s ruling in favor of a consumer who sued a dog food manufacturer for deceptive marketing.

The case, Royal Canin U.S.A., Inc. v. Wullschleger, involved a dispute over a brand of dog food that required a veterinarian’s prescription and was sold at a premium price. The Plaintiff, Anastasia Wullschleger, bought the food, thinking it contained medication not found in ordinary dog food. She later learned it did not. She filed a suit in a Missouri state court, alleging violations of state and federal law. The Defendant, Royal Canin U.S.A., Inc., removed the case to federal court, based on the federal claims. Wullschleger then amended her complaint to delete the federal claims, leaving only state-law claims, and asked the District Court to remand the case to state court. The District Court denied her request and dismissed her case on the merits. The Eighth Circuit reversed, holding that the Federal Court lost its jurisdiction when Wullschleger amended her complaint. This decision highlighted a circuit split. The Eighth Circuit held that jurisdiction is not determined solely at the time of removal, but can be affected by subsequent amendments to the complaint. By contrast, other Circuits, such as the First, Third, Fourth, Sixth, and Eleventh, have held that the existence of subject matter jurisdiction is determined based on the complaint as it existed at the time of removal. Those Circuits maintain that a post-removal amendment cannot divest a federal court of jurisdiction.

The Supreme Court, in a unanimous opinion by Justice Kagan, agreed with the Eighth Circuit and held that the Federal Court had no authority to decide the state-law claims after the amendment. The Court relied on the statute governing supplemental jurisdiction, 28 U.S.C. § 1367, which allows federal courts to hear state-law claims that are related to federal claims within their original jurisdiction. The Court explained that the statute does not distinguish between cases that start in federal court and cases that are removed from state court. Therefore, the same rule applies in both situations: when an amendment eliminates the federal-law claims that enabled jurisdiction, the Federal Court loses its supplemental jurisdiction over the related state-law claims. 

The Court rejected the argument that the statute’s broad language prevents an amendment from divesting jurisdiction, noting that the Court had previously held the opposite in cases that started in federal court. Specifically, the Court referenced its decision in Rockwell Int’l Corp. v. United States, where it held that “when a plaintiff files a complaint in federal court and then voluntarily amends the complaint, courts look to the amended complaint to determine jurisdiction.” This principle, the Court explained, applies regardless of whether the case was originally filed in federal court or removed there. To that end, the Court pointed out that 28 U.S.C. § 1367 does not distinguish between cases removed to federal court and cases originally filed there. Thus, if an amendment in an original case can destroy jurisdiction, the same applies to removed cases. The Court also highlighted that other federal statutes, such as 28 U.S.C. § 1653 and § 1446(b)(3), contemplate that amendments may alter jurisdiction. For instance, § 1653 allows defective allegations of jurisdiction to be amended to ensure a case can proceed, and § 1446(b)(3) permits removal of a case after an amended pleading establishes federal jurisdiction. These statutes reflect Congress’s view—and confirm the Court’s reasoning—that amendments can change the jurisdictional basis of a suit. 

Finally, the Court dismissed as dicta comments in two of its prior cases—dicta in Carnegie-Mellon Univ. v. Cohill, and a footnote in Rockwell—that suggested a different rule for removed cases. In Cohill, the Court made a statement about the District Court’s discretion to retain jurisdiction, but that statement was gratuitous and unsupported by analysis, as the issue in dispute was about how to expel the case, not whether to keep it. Similarly, the footnote in Rockwell, which referred to a special rule for removed cases, was dicta because the case involved an original federal case, not a removed one; thus, the assertion in the footnote went beyond the issue being decided. The Court also emphasized that these dicta were superseded by later authorities, including 28 U.S.C. § 1367 and the Rockwell decision itself, which clarified that jurisdiction should be determined based on the amended complaint.

The Court’s decision reaffirmed the principle that federal courts are courts of limited jurisdiction and that plaintiffs are the masters of their complaints. The Court also recognized the values of federalism and comity that underlie the allocation of jurisdiction between federal and state courts. The Court’s decision may have implications for other cases involving amendments to complaints after removal, such as class actions or diversity cases.