Filed by the plaintiff to send a removed case back to state court. Procedural-defect grounds must be raised within 30 days.
Filed by a plaintiff after a defendant has removed a case from state to federal court, asking the federal court to send it back. Most often based on lack of subject-matter jurisdiction, defective removal procedure, or — for diversity cases — an in-state defendant invoking the forum-defendant rule.
Filed within 30 days of removal in most circumstances. Subject-matter-jurisdiction defects can be raised at any time; procedural defects must be raised within the 30-day window or are waived.
The defendant defends removal by establishing the federal jurisdictional basis — citing the amount in controversy, complete diversity, or the federal question. May move to amend the notice of removal if defective.
Granted (case returns to state court — and remand orders for lack of subject-matter jurisdiction or procedural defects are NOT appealable under 28 U.S.C. § 1447(d)), or denied (case stays in federal court). The plaintiff may recover fees and costs if removal was objectively unreasonable.