Commissioner v. Groetzinger, 480 U.S. 23 (1987), is a decision of the Supreme Court of the United States, which addressed the issue of what qualifies as being either a trade or business under Section 162(a) of the Internal Revenue Code.

[4] The case of Commissioner v. Groetzinger examined what is required for an activity to rise to the level of a "trade or business" for tax purposes.

In the absence of an all-purpose definition by statute or regulation, the Court decided not to create a specific test to determine what qualifies as a trade or business.

[3] The Court found that the constant and large scale effort the taxpayer made towards gambling qualified it being a trade or business.

[3] Under the basic concepts of fairness, the Court held that the ordinary and necessary expenses paid or incurred during the taxable year in carrying out the taxpayer's gambling business could be deducted under the terms of §162(a).