Article I Court
Federal courts come in two structural varieties. Article III courts — the Supreme Court, the federal courts of appeals, and the federal district courts — are established under Article III of the Constitution. Their judges serve “during good Behaviour” with salaries that cannot be diminished. They exercise “the judicial Power of the United States.”
Article I courts are created by Congress under its Article I legislative power. Their judges serve fixed terms. Their jurisdiction is defined by Congress and can be redefined by Congress. They include the U.S. Tax Court, the bankruptcy courts, the Court of Federal Claims, the territorial courts of the District of Columbia and U.S. territories, and military tribunals.
The Tax Court is the canonical example for tax-doctrine analysis. 26 U.S.C. § 7441 declares: “There is hereby established, under article I of the Constitution of the United States, a court of record to be known as the United States Tax Court … The Tax Court is not an agency of, and shall be independent of, the executive branch of the Government.” The statutory designation as Article I is explicit; the emphatic independence-from-executive language distinguishes the Tax Court from administrative adjudicators inside agencies but does not elevate it to Article III status.
Why the distinction matters
When an Article III court issues a decision, it is exercising the constitutional judicial Power. The holding binds lower Article III courts under stare decisis. When it interprets the Constitution, the interpretation is binding authority going forward — it is law that Congress did not pass.
When an Article I court issues a decision, it is adjudicating disputes arising under statutes Congress wrote, in a forum Congress designed, under jurisdiction Congress can adjust. The holding binds the parties and is persuasive to other courts. It is not the same kind of authority as an Article III holding, even when the legal question is identical.
The Supreme Court has worked through the constitutional permissibility of Article I tribunals repeatedly: Glidden Co. v. Zdanok, 370 U.S. 530 (1962); Northern Pipeline Construction Co. v. Marathon Pipe Line Co., 458 U.S. 50 (1982); Stern v. Marshall, 564 U.S. 462 (2011). The doctrinal product is a series of fact-bound holdings without a fully stable underlying theory. The harmonization is not settled.
Practical implication for evaluating claims
When a tax-doctrine claim rests on Tax Court case law, the structural question is part of the evaluation. A Tax Court holding tells you what the Tax Court has decided to do with a provision. It does not, on its own, tell you what an Article III court will do with the same provision on appeal, or how the Supreme Court would resolve the underlying constitutional questions if certiorari were granted.
The methodology page treats this as part of the four-lens evaluation, specifically Lens IV (Legal Tradition): the procedural and remedial features of an Article I tribunal differ from those of common-law adjudication, and the difference can be analytically significant even when the substantive doctrines being applied originate in common-law cases.