28 U.S. Code § 1447 – Post-removal procedure
(a) In any case removed from a State court, the district court may issue all necessary orders and process to bring before it all proper parties whether served by process issued by the State court or otherwise.
(b) It may require the removing party to file with its clerk copies of all records and proceedings in such State court or may cause the same to be brought before it by writ of certiorari issued to such State court.
(c) A motion to remand the case on the basis of any defect other than lack of subject matter jurisdiction must be made within 30 days after the filing of the notice of removal under section 1446(a). If at any time before final judgment it appears that the district court lacks subject matter jurisdiction, the case shall be remanded. An order remanding the case may require payment of just costs and any actual expenses, including attorney fees, incurred as a result of the removal. A certified copy of the order of remand shall be mailed by the clerk to the clerk of the State court. The State court may thereupon proceed with such case.
(d) An order remanding a case to the State court from which it was removed is not reviewable on appeal or otherwise, except that an order remanding a case to the State court from which it was removed pursuant to section 1442 or 1443 of this title shall be reviewable by appeal or otherwise.
(e) If after removal the plaintiff seeks to join additional defendants whose joinder would destroy subject matter jurisdiction, the court may deny joinder, or permit joinder and remand the action to the State court.