in the United States, a court that hears cases involving tax litigation. Originally, a Board of Tax Appeals was set up in 1924 to hear cases in which, for example, a taxpayer might challenge the findings of an Internal Revenue Service agent who had declared a tax deficiency. The board was to act as a body independent of (though cooperating with) the U.S. Department of Justice in the resolution of such cases. In 1942 the board became the Tax Court, which in 1969 became a part of the federal court system.

Its basic jurisdiction lies in determining cases cited as being deficient in the payment of any federal tax (income, gift, estate, etc.). Although centred in Washington, D.C., it may sit in any area of the United States at any given time. A taxpayer may appeal an adverse decision from the Tax Court to the U.S. Court of Appeals, or he may pay the disputed deficiency and then sue for repayment either in a federal District Court or the United States Claims Court.