SCOTUS granted certiorari in Chen v. Mayor and City Council of Baltimore to decided the following question:
"Whether, under Federal Rule of Civil Procedure 4(m), a district court has discretion to extend the time for service of process absent a showing of good cause, as the Second, Third, Fifth, Seventh, Ninth, Tenth, and Eleventh Circuits have held, or whether the district court lacks such discretion, as the Fourth Circuit has held."
Mr. Chen is pro se, but according to The Wall Street Journal the Clerk's office can't find him. Chen's brief is due December 22.
The Fourth Circuit requires a plaintiff to show good cause to justify an extension of the 120-day period for service of process. So, the court dismissed Chen's lawsuit because he failed to show good cause to extend the 120-day period. In addition to the circuits listed in the question on which the Court granted certiorari, the Sixth Circuit seems to also allow district courts the discretion to extend the time absent good cause. The district courts in the First Circuit appear divided on this issue.
The way the courts interpret Rule 4 (m) in most of the circuits the plaintiff courts must extend the 120-day period if the plaintiff shows good cause, but even without good cause the district courts have the discretion to extend the time for service.
The Supreme Court is poised to resolve the issue in Chen.