After the defendant has removed a class action to federal court under CAFA, the plaintiff may not amend the alleged class definition to exclude all class members who are citizens of states different from defendant, thus destroying minimal diversity and CAFA jurisdiction. CAFA jurisdiction is determined based on the pleadings as they stand on the date the notice of removal is filed. Later amendments do not count. Benko v. Quality Loan Service Corp. (9th Cir. 2015) 789 F.3d 1111 allows only a very narrow exception to this rule, allowing a plaintiff to amend, after removal, to amplify his complaint solely to show that his claims against the in-state defendant were significant so as to invoke the local controversy exception to CAFA jurisdiction. The exception was justiified on the ground that the amendment addressed a CAFA-specific issue that the plaintiff would be unlikely to mention in his normal state-court complaint. Class definition, by contrast, is a normal element of a state court complaint, and not anything CAFA-specific. Accord: Hargett v. RevClaims, LLC (8th Cir. 2017) 2017 WL 1405034; Reece v. AES Corp. (10th Cir. 2016) 638 Fed.Appx. 755, 775.
Ninth Circuit Court of Appeals (Schroeder, J.; Rawlinson, J., dissenting); May 18, 2017; 2017 WL 2174549