Severing claims in a civil case means splitting one lawsuit into two or more independent cases, each with its own docket number, schedule, and final judgment. Under Federal Rule of Civil Procedure 21, a judge can order severance at any time, either on a party’s motion or on the court’s own initiative, when the claims don’t belong in the same proceeding.1Legal Information Institute. Federal Rules of Civil Procedure Rule 21 – Misjoinder and Nonjoinder of Parties Once severance happens, the severed claim is no longer part of the original lawsuit at all. That single fact drives most of what parties care about: new filing fees, independent appeal rights, separate discovery, and the possibility of transfer to a different court.
Severance Is Not the Same as a Separate Trial
The distinction between severance under Rule 21 and separate trials under Rule 42(b) catches even experienced litigators, and it matters. Separate trials (sometimes called bifurcation) keep everything under one case number. The court tries different issues at different times. A products case might take up liability first and damages second. Both phases share the same docket, discovery, and ultimate judgment.
Severance goes further. The clerk opens a new file, assigns a new docket number, and from that point forward the severed claim lives or dies on its own. It gets its own scheduling order, its own trial date, and its own appealable judgment. If you need the two sets of claims resolved truly independently, severance is the right tool. If you only need the trial itself broken into phases, ask for separate trials instead and avoid the duplication.
The Standard Courts Apply
Rule 21 is brief. It says the court “may also sever any claim against a party” and can do so “at any time, on just terms.”1Legal Information Institute. Federal Rules of Civil Procedure Rule 21 – Misjoinder and Nonjoinder of Parties It doesn’t lay out a multi-factor test, so federal courts have built one through case law. Three considerations tend to carry the weight: whether a joint proceeding would prejudice a party, whether severance promotes judicial economy, and whether a combined trial would confuse the jury.
Rule 20’s joinder standard supplies the backdrop. Parties belong in one lawsuit only when their claims arise out of the same transaction or series of transactions and share at least one common question of law or fact.2Legal Information Institute. Federal Rules of Civil Procedure Rule 20 – Permissive Joinder of Parties When claims flunk that test, they’re misjoined and severance is the natural fix. Even where joinder is technically proper, the court keeps discretion to sever. The Eighth Circuit’s decision in Mosley v. General Motors Corp. described the balancing act: federal procedure favors broad joinder to cut delay and expense, but trial courts may order separate proceedings when necessary to prevent prejudice.3Open Casebook. Mosley v General Motors Corp
Prejudice Is Usually the Winning Argument
Prejudice moves the needle most often. The classic scenario: a case with multiple defendants where inflammatory evidence against one would bleed over and taint the jury’s view of another. If one defendant faces fraud allegations backed by dramatic testimony while a co-defendant is accused of a routine contract breach, a joint trial risks tarring both with the same brush. Courts take this risk seriously because it strikes at the fairness of the trial itself.
Judicial Economy Can Cut Either Way
Severance creates more work for the court. Instead of one case, the judge now manages two. Instead of one trial, there may be two. The movant has to explain why the extra cost is worth it. Arguments that tend to land: the claims need entirely different witnesses, the legal theories are unrelated, or a combined trial would run so long jurors couldn’t keep the issues straight. Vague preferences or minor inconvenience will not do it.
When It Makes Strategic Sense to Ask
Not every party who could request severance should. The decision involves real trade-offs.
Defendants often want severance when they’re grouped with a co-defendant who looks worse. The defendant accused of negligent oversight has a strong incentive to get out of the courtroom before the fraud evidence against a co-defendant poisons the jury. Severance removes the spillover entirely, because the jury in the severed case never hears the other defendant’s story.
Plaintiffs sometimes resist severance because keeping everything together creates settlement leverage. A defendant facing one large trial with overlapping witnesses and heavy preparation costs may pay more to make it go away than it would if each claim stood alone. Other plaintiffs push for severance themselves when one claim is strong and another is weak, so the weaker claim doesn’t drag the stronger one down at trial.
Complexity is a third driver. When so many parties and claims are packed into one case that no jury could reasonably digest it, severance simplifies the picture. Courts are more receptive when the movant can show the combined trial would run weeks or months across fundamentally distinct subject matter.
Filing the Motion
A motion to sever needs to do three things clearly: identify which claims or parties should be separated, explain why they don’t belong together, and describe the harm of keeping them joined. Judges want specifics. “The claims are unrelated” is a conclusion, not an argument. Show which transactions gave rise to which claims and why the factual overlap is too thin to justify one trial.
Include the full case caption and docket number. Most courts expect a supporting memorandum organized around prejudice, judicial economy, and jury confusion. Declarations or affidavits help when the prejudice argument depends on specific evidence that would come out at a joint trial. Many federal districts also require a certificate of conference showing that the movant’s attorney spoke with opposing counsel before filing. Local rules on formatting, page limits, and pre-filing conferences vary, so check them before you draft.
Rule 21 does not set a deadline for a severance motion. The court can sever “at any time,” and parties can raise the issue at nearly any stage.1Legal Information Institute. Federal Rules of Civil Procedure Rule 21 – Misjoinder and Nonjoinder of Parties That said, a motion filed the week before trial gets a far colder reception than one filed early. If the misjoinder was clear from the complaint, the judge will reasonably ask why you waited.
Response Time for the Other Side
The Federal Rules do not fix a specific number of days to oppose a severance motion. Rule 6(c)(1) requires that a motion and hearing notice be served at least 14 days before the hearing, and local rules in each district set the actual response deadline.4Legal Information Institute. Federal Rules of Civil Procedure Rule 6 – Computing and Extending Time; Time for Motion Papers In many districts, that falls between 14 and 21 days after service. Once briefing closes, the judge sets oral argument or rules on the papers.
Proposed Orders
Some courts expect a proposed order with the motion. A good proposed severance order says which claims are being severed, directs the clerk to open a new case file, and addresses what happens next, whether that means transferring the severed claims to a new docket, remanding them to state court, or sending them to a different federal district. Check the presiding judge’s individual practices before submitting one.
What Changes Once Severance Is Granted
When the judge signs the order, the clerk opens a new file and assigns a fresh docket number. From that moment, every filing on the severed claim goes to the new docket. Filing under the old number is a common error that creates delays. The severed case proceeds independently with its own scheduling order, its own discovery deadlines, and potentially a different trial judge. Settlement talks in one case have no formal bearing on the other, and a verdict in one does not resolve the other.
You Will Likely Owe a New Filing Fee
Severance usually triggers a new filing fee because the severed claim is treated as a new civil action. In federal court, the filing fee under the statute is $350, plus a $55 administrative fee, for a total of $405.5Office of the Law Revision Counsel. 28 USC 1914 – District Court; Filing and Miscellaneous Fees State court fees vary. This can catch parties off guard, especially when severance is granted over their objection and they suddenly owe hundreds of dollars to keep the claim moving.
Discovery Does Not Coordinate Itself
Severed claims are legally independent but often share witnesses, documents, and experts. Rule 42(a) lets a court consolidate discovery or coordinate hearings across related cases to avoid duplication.6Legal Information Institute. Federal Rules of Civil Procedure Rule 42 – Consolidation; Separate Trials Parties in severed cases sometimes stipulate to share deposition transcripts or use the same expert reports, which saves real money. None of this happens on its own. If no one asks for coordination, each case proceeds in its own silo and you may end up paying to depose the same witness twice.
The Severed Case Can Be Transferred Separately
Once severed, a claim can be transferred to a different federal district independently of the original action. This comes up when multiple defendants were joined in one forum but a severed claim has a stronger connection to a different courthouse. The usual convenience-of-parties analysis applies, limited to the parties and witnesses relevant to the severed claim. Severance followed by transfer is a recognized play for a defendant pulled into an inconvenient forum alongside co-defendants with real ties there.
Extra Costs Beyond the Filing Fee
The filing fee is only the start. Severed cases generate their own pretrial motions, trial preparation, and potentially duplicate expert work. The same expert testifying in both cases usually means two appearances, two reports, and two rounds of deposition preparation. Court reporter costs double if both go to trial. Attorney time rises because counsel tracks two sets of deadlines, attends two sets of hearings, and prepares two sets of jury instructions. Weigh these against the alternative. Sometimes the prejudice from a joint trial justifies the cost. Other times a limiting instruction or separate trials under Rule 42(b) keeps the claims under one case number and avoids the duplication.
Severance Unlocks Immediate Appeal Rights
One of severance’s most important consequences is what it does to appeals. In a multi-claim case that hasn’t been severed, you generally cannot appeal a ruling on one claim until every claim is resolved. Rule 54(b) offers a narrow exception: the trial court can certify a partial judgment as final if it “expressly determines that there is no just reason for delay.”7Legal Information Institute. Federal Rules of Civil Procedure Rule 54 – Judgment; Costs That certification is not guaranteed, and courts are often reluctant to give it.
Severance sidesteps the problem. Because the severed claim is its own case, a final judgment in it is immediately appealable without any Rule 54(b) certification. The parties don’t have to wait for the original lawsuit to finish. That can matter for a defendant who wins summary judgment on the severed claim and wants to lock in the result before anything else happens.
What Severance Does to the Statute of Limitations
A severed claim generally keeps the original filing date for limitations purposes. Because the claim was part of the complaint when it was filed, the filing date relates back to the original action, and the claim isn’t treated as if it were filed fresh on the date of severance. The analysis gets more complicated if severance involves adding new parties or claims that weren’t in the original pleading. If you’re near a limitations deadline and facing possible severance, raise the issue with the court directly and ask for a clear statement in the severance order.
When the Judge Severs on Her Own
Parties aren’t the only ones who can start severance. Rule 21 lets the court sever claims “on its own” without any motion.1Legal Information Institute. Federal Rules of Civil Procedure Rule 21 – Misjoinder and Nonjoinder of Parties This usually happens when a judge concludes that the joined claims have little in common or that a combined trial would be unmanageable, and it also shows up in cases that have ballooned to include dozens of plaintiffs with individualized claims. Courts generally invite briefing before entering the order, but the decision is discretionary. The appellate standard is abuse of discretion, which is a hard bar to clear.3Open Casebook. Mosley v General Motors Corp