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 New York, as in other states, a defendant has the right to remove a lawsuit from state court to federal court under certain conditions. This can occur if the case involves a federal question, meaning the plaintiff's claim is based on federal law, or if there is diversity of citizenship, where no plaintiff shares the same state citizenship with any defendant. The latter also requires that the amount in controversy exceeds $75,000. Once the defendant initiates the removal by filing the necessary documents with the federal court, the plaintiff has 30 days to challenge the removal. The plaintiff can file a motion to remand the case back to state court if they believe the federal court lacks jurisdiction. The federal court will then decide whether to keep the case or remand it to the state court.