In 1968, Congress enacted the Federal Magistrates Act to enhance judicial efficiency in the federal courts. Since then, some judicial functions delegated to magistrate judges have been challenged on constitutional grounds: while federal district judges, appointed pursuant to Article III of the United States Constitution, are protected with life tenure and undiminishable salary, thereby enhancing judicial independence, federal magistrate judges, appointed pursuant to Article I, have no such protection. The most recent major challenge to magistrate judge authority came in 2001, when the United States Court of Appeals for the Fifth Circuit, in United States v. Johnston, decided that referral to magistrate judges for final disposition of federal prisoner 28 U.S.C. § 2255 post-conviction motions, with the consent of the parties, violates Article III. This Article traces the evolution of the Federal Magistrates Act, explores constitutional and other challenges that have arisen under the Act and how the courts have resolved them, and reviews the unique nature of § 2255 motions. Professor Robbins argues against referral of § 2255 motions to magistrate judges for final disposition, and concludes with recommendations of other ways to deal with these motions without overloading the judicial system.