The Court of Appeals may raise sua sponte a question as to whether CAFA jurisdiction exists in a removed action even though neither the plaintiff nor the district court challenged the defendant’s removal of the action or questioned the existence of CAFA jurisdiction. Here, neither the removal notice nor an attached declaration established that CAFA’s $5 million amount in controversy requirement was satisfied. The individual plaintiff sought less than $1,000 in damages. The alleged class included only drivers injured by other drivers that GEICO had insured in Montana. Neither the number of class members nor the average or range of potential damages per class member was established by the record before the court. The Ninth Circuit vacated the judgment and remanded for the district court to conduct evidentiary proceedings to resolve whether the amount in controversy requirement was satisfied.