	Introduction

The U.S. Constitution established only one federal court—the U. S. Supreme Court. In the years following the ratification of the Constitution, Congress has regularly exercised its power to create a host of different federal tribunals that adjudicate a variety of legal disputes. The two central types of federal "courts"—courts established under Article III and those tribunals that are not—differ in many respects, including with regard to their personnel, purposes, and powers. Article III or Constitutional Courts

Courts established pursuant to Article III are mainly defined by the three central constitutional provisions to which they are subject. The Constitution did this by "insulating the federal judiciary" from potential pressures, from either the political branches or the public, which could potentially "skew the decision making process or compromise the integrity or legitimacy of federal court decisions." Non-Article III or Legislative Courts

As noted above, Article III of the Constitution commands that "the judicial Power of the United States, shall be vested in one Supreme Court, and in such inferior courts as the Congress may from time to time ordain and establish." Notwithstanding this command, Congress has assigned to non-Article III bodies—that is, forums with judicial officers who do not enjoy Article III guarantees—the authority to adjudicate a large swath of cases that would seemingly fall within the "judicial power" traditionally allocated to Article III courts. There are two main categories of non-Article III courts. The first is commonly referred to as "legislative courts" or "Article I courts." These are standalone courts, created under Congress's Article I power, which have similar authority as Article III courts, such as entering their own judgments and issuing contempt orders. Examples of legislative courts include the U.S. Tax Court; the Court of Federal Claims; the Court of Appeals for Veterans Claims; the Court of Appeals for the Armed Forces; and federal district courts in Guam, the Virgin Islands, and the Northern Mariana Islands. The second category of non-Article III tribunals has commonly been referred to as "adjuncts" to Article III courts. This category is mainly comprised of federal administrative agencies and magistrate judges. Finally, Congress has established non-Article III tribunals to avoid the constitutional restrictions imposed upon Article III courts. An "adjunct" is an adjudicator—most often an administrative agency or a magistrate judge—that does not function as an independent court, but instead acts as a subordinate to the federal courts. These agencies perform a host of various functions including making policy, promulgating rules, and adjudicating questions arising under federal law. For example, under the Federal Magistrates Act, upon the consent of the parties, a magistrate judge "may conduct any or all proceedings in a jury or nonjury civil matter and order the entry of judgment in the case.... " Moreover, pursuant to the Bankruptcy Amendments and Federal Judgeship Act of 1984, a district court, with the "consent of all parties to the proceeding," is permitted to refer a "proceeding related to a case under title 11 to a bankruptcy judge to hear and determine and to enter appropriate orders and judgments.... " Other federal laws may provide for arbitration over discrete legal issues to occur based on the consent of the parties involved.
The U.S. Constitution established only one federal court—the U.S. Supreme Court. Beyond this, Article III of the Constitution left it to the discretion of Congress to "ordain and establish" lower federal courts to conduct the judicial business of the federal government. From the very first, Congress established a host of different federal tribunals to adjudicate a variety of legal disputes. The two central types of federal "courts"—courts established under Article III and those tribunals that are not—differ in many respects, including with regard to their personnel, purposes, and powers.
Courts established pursuant to Article III are mainly defined by the three central constitutional provisions to which they are subject: resolution of cases that only present live "cases or controversies," lifetime tenure, and salary protection. The primary purpose for these safeguards was to insulate the federal judiciary from potential pressures, from either the political branches or the public, which might improperly influence the judicial decision-making process.
Notwithstanding Article III's seemingly literal command that the "judicial power" shall extend to all cases "arising under" the Constitution or federal law, Congress has assigned a host of cases arising under federal law to non-Article III bodies. Unlike Article III judges, these bodies, generally referred to as "non-Article III courts," "legislative courts," or "Article I courts," enjoy neither lifetime tenure nor salary protection. There are two main categories of non-Article III courts. The first are standalone courts, created under Congress's Article I power, which have similar authority as Article III courts, such as entering their own judgments and issuing contempt orders. Examples of legislative courts include the U.S. Tax Court; the Court of Federal Claims; the Court of Appeals for Veterans Claims; the Court of Appeals for the Armed Forces; and federal district courts in Guam, the Virgin Islands, and the Northern Mariana Islands. The second category of non-Article III tribunals is commonly referred to as "adjuncts" to Article III courts. This category is mainly comprised of federal administrative agencies and magistrate judges.
These non-Article III bodies have been justified on several grounds. First, the Court has held that in certain limited instances, Article III's absolute command must give way to Congress's exercise of its Article I powers. This theory has been used to justify the creation of territorial courts, military courts, and the adjudication of cases involving rights created by Congress (commonly referred to as "public rights" cases). The second rationale is the use of "adjuncts," judicial officers who do not function as independent courts but instead act as a subordinate to the federal courts with direct review of their decisions. Examples of adjuncts include the thousands of administrative law judges who adjudicate cases coming before federal agencies and federal magistrate judges who assist district court judges with everything from deciding motions, hearing evidence, and trying both criminal and civil cases. Lastly, certain questions arising under federal law may be resolved by non-Article III tribunals if the parties to the proceeding consent to such an adjudication.