When State and Federal Courts Have Concurrent Jurisdiction

Concurrent jurisdiction between state and federal courts exists when a case qualifies for both systems because Congress has not reserved the subject for federal court alone. The two most common triggers are diversity of citizenship, where opposing parties come from different states and more than $75,000 is at stake, and federal-law claims that Congress left open to state courts. The plaintiff picks the forum first by choosing where to file. The defendant then often has the power to override that choice by removing the case to federal court, which makes the jurisdictional question one of the most consequential early decisions in any lawsuit.

When Both Courts Can Hear the Same Case

Federal courts are courts of limited jurisdiction. They can only hear cases that fall within a specific grant of authority from the Constitution or a federal statute. State courts are courts of general jurisdiction and can hear almost anything, including most claims arising under federal law. The overlap is wide.

Two gateways open the federal courthouse door. Federal question jurisdiction covers any civil case “arising under the Constitution, laws, or treaties of the United States,” with no minimum dollar amount.1Office of the Law Revision Counsel. 28 USC 1331 – Federal Question Diversity jurisdiction applies when the opposing parties are citizens of different states and the amount in controversy exceeds $75,000, not counting interest or costs. For corporations, citizenship runs to both the state of incorporation and the state of the principal place of business, so a company incorporated in Delaware and headquartered in California counts as a citizen of both.2Office of the Law Revision Counsel. 28 USC 1332 – Diversity of Citizenship; Amount in Controversy; Costs

Multiple claims against the same party can be added together to reach the $75,000 threshold. Stacking alternative legal theories for a single injury does not count, because the maximum recovery stays the same regardless of which theory wins.

Concurrent jurisdiction grows out of this structure in two ways. Nearly every diversity case qualifies for both systems, so a personal injury suit between citizens of different states worth $100,000 can go to either the plaintiff’s state court or the appropriate federal district court. And many federal statutes create a right of action without stripping state courts of authority to hear it. Federal employment discrimination laws, consumer protection statutes, and civil rights claims commonly fall in this category. Unless Congress explicitly reserves the claim for federal courts, the presumption is that state courts share jurisdiction.

Class actions sit in their own slice of the overlap. Under the Class Action Fairness Act, federal courts have jurisdiction over class actions with at least 100 putative members, minimal diversity between the parties, and more than $5 million in aggregate controversy.2Office of the Law Revision Counsel. 28 USC 1332 – Diversity of Citizenship; Amount in Controversy; Costs These cases can still be filed in state court, but defendants frequently remove them to federal court for the procedural environment.

Why the Choice of Court Matters

When both courts can hear a case, the choice is genuinely strategic. A few differences do most of the work:

  • Jury rules. Federal civil trials require a unanimous verdict from at least six jurors unless the parties agree otherwise. Many state courts allow non-unanimous verdicts or use larger panels, which can favor one side or the other depending on the local jury pool.3Legal Information Institute (LII). Federal Rule of Civil Procedure 48 – Number of Jurors; Verdict; Polling
  • Speed. Federal courts often carry heavier civil caseloads, meaning longer waits for trial. Some state courts move faster, though this varies by county.
  • Discovery and procedure. Federal courts follow the Federal Rules of Civil Procedure, with strict discovery deadlines and pretrial requirements. State procedural rules can be more flexible or more restrictive.
  • Applicable law. Under the Erie doctrine, a federal court hearing a diversity case applies the substantive law of the state where it sits, while procedural rules stay federal. The legal standards for liability and damages are the same in either court; the procedural path to get there is not.
  • Judicial experience. Federal judges handle federal statutory claims regularly and may be more comfortable with complex regulatory questions. State court judges often have deeper experience with the state-law causes of action that make up the bulk of concurrent cases.

Removal: How Defendants Override the Plaintiff’s Choice

The plaintiff gets to choose the initial forum, but the defendant is not stuck with that choice. Under federal law, a defendant can remove most cases from state court to the federal district court covering the same geographic area, provided the case could have originally been filed in federal court.4Office of the Law Revision Counsel. 28 USC 1441 – Removal of Civil Actions This is the practical muscle behind concurrent jurisdiction. A plaintiff who files in state court to gain a perceived advantage can be pulled into federal court by the other side.

The 30-Day Deadline

A defendant who wants to remove has to act fast. The notice of removal must be filed within 30 days after the defendant receives the initial complaint or summons, whichever comes first. The notice goes to the federal district court covering the location of the state case and must include a short statement of the grounds for removal along with copies of all pleadings and orders from the state case.5Office of the Law Revision Counsel. 28 USC 1446 – Procedure for Removal of Civil Actions After filing, the defendant must promptly notify all opposing parties and the state court clerk.

Sometimes a case that was not removable at the outset becomes removable later, such as when an amended complaint pushes the amount in controversy past $75,000 or adds a federal claim. In that situation, the defendant gets a fresh 30-day window from the point the case first becomes removable. For diversity cases, there is also an absolute one-year deadline from the date the case was originally filed in state court.6Office of the Law Revision Counsel. 28 U.S. Code 1446 – Procedure for Removal of Civil Actions The only exception to the one-year cap is when the plaintiff deliberately manipulated the case to prevent removal, such as by keeping the claimed damages artificially low until the deadline passed.

The Forum Defendant Rule

Diversity cases carry one important exception. A defendant who is a citizen of the state where the lawsuit was filed cannot remove the case to federal court based solely on diversity jurisdiction.7Office of the Law Revision Counsel. 28 U.S. Code 1441 – Removal of Civil Actions The logic tracks the original purpose of diversity jurisdiction: if the defendant is a local, there is no risk of hometown bias. So if you sue a Texas company in Texas state court, that company cannot remove to federal court on diversity grounds alone, even if all other diversity requirements are met.

Cases Congress Keeps in State Court

Congress has also carved out specific categories of cases that stay in state court no matter what. Federal law prohibits removal of claims brought under the Federal Employers’ Liability Act, which covers railroad workers injured on the job, and of state workers’ compensation claims.8Office of the Law Revision Counsel. 28 U.S. Code 1445 – Nonremovable Actions Concurrent jurisdiction technically exists for FELA claims, but the defendant cannot use removal to shift the case to federal court.

Fighting Removal: Motions to Remand

If a plaintiff believes the removal was improper, the remedy is a motion to remand asking the federal court to send the case back. The deadline depends on the defect. For procedural problems like a late filing or a failure to include all defendants in the removal notice, the motion must be filed within 30 days after the notice of removal.9Office of the Law Revision Counsel. 28 U.S. Code 1447 – Procedure After Removal Generally

A challenge based on lack of subject matter jurisdiction has no deadline. If the federal court lacks authority over the case, it must send the case back at any point before final judgment, even if neither party raises the issue.9Office of the Law Revision Counsel. 28 U.S. Code 1447 – Procedure After Removal Generally This is where removal attempts most often fall apart. A defendant removes the case, the plaintiff files a remand motion arguing that diversity is incomplete or the federal claim is too weak, and the court agrees.

State Claims That Ride Along in Federal Court

Once a case is properly in federal court on a federal question, the court can also hear related state-law claims that grow out of the same set of facts. This is supplemental jurisdiction, and it exists so parties do not have to split a single dispute between two court systems.10Office of the Law Revision Counsel. 28 USC 1367 – Supplemental Jurisdiction If you sue your employer in federal court for violating a federal wage law and also want to bring a state breach-of-contract claim based on the same conduct, the federal court can handle both.

Federal judges are not required to accept every tag-along state claim. A court may decline supplemental jurisdiction when the state-law claim raises a novel or complex question of state law, when the state claims substantially overshadow the federal claim, when all federal claims have been dismissed, or when other compelling circumstances weigh against keeping the state claims.10Office of the Law Revision Counsel. 28 USC 1367 – Supplemental Jurisdiction In practice, federal courts routinely drop state claims after the anchor federal claim is dismissed early in the case, sending the plaintiff back to state court to continue.

Cases Only Federal Courts Can Hear

Concurrent jurisdiction has limits. Congress has reserved certain categories of cases exclusively for federal courts, meaning state courts have no authority to hear them at all. The most important exclusive areas are:

If a case falls into one of these exclusive categories, filing in state court is a jurisdictional dead end. The state court must dismiss, and the plaintiff has to refile in federal court, potentially losing time and money in the process.