Code Federal tax law begins with statutes or laws enacted by the U.S. Congress. These statutes are then codified or organized. Codified statutes are referred to as a "Code". Title 26 U.S.C. (United States Code) is the codification of the Internal Revenue statutes or laws.
Regulations are the detailed rules which articulate how statutes or laws will be enforced. Regulations are created by executive branches of the government. Title 26 C.F.R. (Code of Federal Regulations) covers regulations created by the Department of Treasury related to Internal Revenue. Note that regulations are also codified.
Case Law Opinions rendered by appeals court decisions constitute the body of case law, which continually evolves as courts interpret laws and regulations. Tax Court Memorandum (TCM) Court decisions deal with substantive tax matters when there is a dispute between the IRS and the taxpayer. TCM decisions are available at the US Tax Court website.
Administrative Rulings or revenue rulings, are public administrative rulings by the Internal Revenue Service (IRS). They apply the law to issues or situations not addressed by the code, regulations, or case law. Public administrative rulings are subordinate to the Internal Revenue Code and other statutes, Treasury regulations, treaties and court decisions.
Administrative/revenue rulings are published in the Internal Revenue Bulletin (IRB). The IRB, however, is easily searched via Lexis-Nexis Uni, but you'll need to filter out other sources--to do that, click on Advanced Options, and deselect everything except the IRB.
A statute is the law as passed by the U.S. Congress or a State Legislature.
Statutory laws are published in two forms: A chronological form exactly as passed by the legislature, and a codified form, which arranges the law by topic and removes all superseded and repealed laws. Codified statutes are referred to as a "code,"
Statute sources:
Regulations are the detailed rules which articulate how statutes will be enforced. They have the force of law.
Regulations are created by administrative agencies of the executive branch of government.
Regulations are also generally published in two versions: Chronologically, and codified--which arranges the regulations by subject.
Regulation sources:
Courts interpret statutes and regulations.
Broadly speaking, there are are two types of courts: trial courts and appeals courts.
Findings of fact and law are made in the trial court. These findings or decisions may be appealed to an appeals court, which has the power of review. Appeals courts, appellate courts or a court of appeals determine whether statutes and regulations have been applied fairly and correctly in trial courts or a lower appeals court.
Opinions rendered by appeals court decisions constitute the body of case law, which continually evolves as courts interpret laws and regulations.
Sources for tax case law:
Administrative Rulings, or revenue rulings, are public administrative rulings by the Internal Revenue Service (IRS). They apply the law to issues or situations not addressed by the code, regulations, or case law. Public administrative rulings are subordinate to the Internal Revenue Code and other statutes, Treasury regulations, treaties and court decisions.
Sources for Administrative Rulings:
