It is
a familiar rule of administrative law that an agency must abide by its own regulations. Vitarelli v. Seaton, 359 U. S. 535, 547 (1959); Service v. Dulles, 354 U. S. 363, 388 (1957). Quoted in Fort Stewart Schools v. FLRA, 495 U.S. 641, 654, 110 S.Ct. 2043, 2051, 109 L.&l.2d 659 (1990)
4.10.7.2.8.8 (01-01-2006)
Importance of Court Decisions
(1) Decisions made at various levels of the court system are considered to be interpretations of tax laws and may be used by either examiners or taxpayers to support a position.
(2) Certain court cases lend more weight to a position than others. A case decided by the US Supreme Court becomes the law of the land and
takes precedence over decisions of lower courts. The IRS must follow Supreme Court decisions. For examiners, Supreme Court decisions have the same weight as the IRC.
(3)Decisions made by lower courts, such as Tax Court, District Courts, or Claims Court, are binding on the IRS only for the particular taxpayer and the years
litigated. Adverse decisions of lower courts do not require the IRS to alter its position for other taxpayers.