High Quality Content by WIKIPEDIA articles! The United States of America Mathematical Olympiad (USAMO) is a prestigious high school mathematics competition held annually in the United States. Since its debut in 1972, it has served as the final round of the AMC series of contests. Top scorers on the USAMO usually represent the United States at the International Mathematical Olympiad. In order to be eligible to take the USAMO, a participant must be either a U.S. citizen or a legal resident of the United States or Canada. Only U.S. residents and citizens may join the American IMO team. In addition, all participants, regardless of geographic location, must meet qualification indices determined by previous rounds of the AMC contests. Entry to the USAMO is by invitation only.