The step transaction doctrine is a judicial doctrine in the United States that combines a series of formally separate steps, resulting in tax treatment as a single integrated event. The doctrine is often used in combination with other doctrines, such as substance over form. The doctrine is applied to prevent tax abuse, such as tax shelters or bailing assets out of a corporation. The step transaction doctrine originated from a common law principle in Gregory v. Helvering, 293 U.S. 465 (1935), which allowed the court to recharacterize a tax-motivated transaction.