A foreign corporation in which more than 50% of the total combined voting power of its stock or the total value of its stock is owned by "United States shareholders." The Tax Cuts and Jobs Act (Act) expanded the definition of "United States shareholder." Under pre-Act law, a US shareholder for CFC purposes is a US person (IRC § 957(c)) who owns 10% or more of the total combined voting power of all classes of stock entitled to vote of the foreign corporation (IRC § 951(b)). Under the Act, the definition of a US shareholder is expanded to also include any US person who owns 10% or more of the total value of shares of all classes of stock of a foreign corporation (IRC § 951(b). This new definition is effective for taxable years of foreign corporations beginning after December 31, 2017, and for taxable years of United States shareholders in which or within which those taxable years of foreign corporations end. This new definition will likely increase the number of foreign corporations that are classified as CFCs.