If a lawsuit is filed in state court, the defendant may remove the lawsuit to federal court if there is a basis for the federal court to have jurisdiction over the lawsuit—either because the plaintiff has alleged a violation of federal law (the U.S. Constitution, a federal statute, or a treaty to which the United States is a party), or because there is complete diversity of citizenship between the parties—meaning no plaintiff is a citizen of the same state as any defendant—whether the parties are persons or entities.

If the defendant files the documents necessary to remove a lawsuit filed in state court to federal court, the plaintiff then generally has 30 days to request the federal court remand (send) the lawsuit back to the state court on the basis that the federal court does not have jurisdiction over the matter.

In Arizona, as in other states, a defendant has the right to remove a lawsuit from state court to federal court if certain conditions are met. This can occur if the case involves a federal question, meaning that the plaintiff alleges a violation of federal law, such as the U.S. Constitution, federal statutes, or treaties. Additionally, a case can be removed based on diversity jurisdiction, which exists when all plaintiffs are citizens of different states than all defendants, and the amount in controversy exceeds $75,000. Upon removal, the plaintiff may challenge the transfer by filing a motion to remand the case back to state court within 30 days, arguing that the federal court lacks jurisdiction. The federal court will then determine whether it has the authority to hear the case or if it should be remanded to state court.