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Commissioner v. Idaho Power Co.

United States Supreme Court
418 U.S. 1 (1974)


The value of equipment owned by Idaho Power Company (IPC) (plaintiff) depreciated through the equipment’s use in daily operations and maintenance and in the construction of IPC’s capital improvements. Under § 167(a) of the federal tax code, the equipment’s operations- and maintenance-related depreciation entitled IPC to a business-expense tax deduction from IPC’s current gross income. IPC also claimed a § 167(a) deduction for its capital-construction-related equipment depreciation. The commissioner of internal revenue (defendant) denied IPC’s capital-construction-related depreciation deduction because the depreciation was a capital expenditure, which § 263(a)(1) of the tax code required to be computed over the useful life (30 years or more) of IPC’s new capital facilities. IPC petitioned the United States Tax Court for a redetermination. The tax court found for the commissioner, and the court of appeals reversed in favor of IPC. The United States Supreme Court granted certiorari.

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