District Judge or Magistrate Judge: Which Rules Apply to a Discovery Dispute

Suppose opposing counsel won't produce a key witness for deposition, and you decide to file a motion to compel.

The judge assigned to the case is Judge Michael A. Shipp (D.N.J.), and his Individual Practices set a 25-page limit. You draft a 15-page brief, file it on ECF and wait.

Then a text order appears on the docket:

The ten billable hours spent on the brief are lost, because nobody will read it, and the client is billed for work that accomplished nothing.

Firms often miss which judge's rules apply when a case has both a District Judge and a Magistrate Judge.

What Happened in Cox v. Chrysler

Cox v. Chrysler (D.N.J.) had two judges whose rules were very different.

Judge Shipp, the District Judge, handled trial, sentencing, and dispositive motions like summary judgment and motions to dismiss. His rules set a 25-page limit on briefs, 12pt Times New Roman and spiral-bound courtesy copies.

Magistrate Judge Arpert handled everything else, including discovery, scheduling and settlement conferences, and her rules allowed no formal briefs. Discovery disputes required a joint letter of at most 3 pages for both sides together. Settlement statements went to chambers by email, ex parte, so the other side never saw them.

PACER lists Judge Shipp as the "Presiding Judge." So if you just look at the docket header and pull his standing order, you'll follow the wrong rules for every single discovery filing. And in a case like Cox, discovery is where most of the action happens.

Why a case has two judges

Under 28 U.S.C. § 636, District Judges can refer pretrial matters to Magistrate Judges. In busy districts like D.N.J., S.D.N.Y., and E.D.N.Y., the referral is automatic for all civil cases, so no party has to request it.

The split depends on whether the motion is dispositive. Summary judgment motions, motions to dismiss and class certification stay with the District Judge. Everything else, such as discovery scope, deposition disputes, interrogatory objections, scheduling extensions and settlement, goes to the Magistrate.

The dividing line decides which standing order controls a filing, so the formatting rules, page limits and submission procedures in one case depend on which judge will read the filing.

Common mistakes

Filing a formal motion to compel. Most Magistrate Judges want a joint letter outlining the dispute instead of a motion. A formal motion event on ECF tells the court the filer hasn't read the standing order, and the motion gets bounced before the judge considers the merits.

Filing a settlement statement on ECF. Magistrate Judge Arpert, and many others, require settlement statements to be emailed directly to chambers, because they contain the client's bottom-line number. A statement filed on ECF shows that number to opposing counsel before the settlement conference.

Assuming the Magistrate handles motions to seal. In Cox, sealing motions related to discovery were decided by the Magistrate, but the standards for redaction and binder formatting often defaulted to the District Judge's preferences because the documents might be used at trial later. A filing that gets this wrong has to be re-filed publicly.

How to check which rules apply

First, check the docket header for a referral judge before any filing. Second, decide whether the motion is dispositive, because that decides which judge's standing order you need. Third, for a discovery dispute, look for the Magistrate Judge's own protocol. About 90% of them have one, and it's almost always a joint letter with a strict page limit, usually 3 to 5 pages. Before a settlement conference, find out whether the statement goes on ECF or by email to chambers.

These rules are all in the standing orders, but few people read two sets of standing orders for one case, and the docket header shows only one judge's name. CourtRules.app flags when a District Judge has a Magistrate referral, so you know which rules apply before you file.