The need to ensure equal rights to different age groups without discrimination in our country necessitates the study of international experience. One of the traditional and at the same time, urgent problems in the USA is the problem of age equality and the overcoming of discriminatory theory and practice. The goal of the study is to analyze the genesis of the system of legal safeguards against age discrimination in the U.S. legislation and the practice of the United States Supreme Court. Methodological potential includes methods of comparative historical and legal analysis. The development of the United States Supreme Court and other federal courts on age discrimination was investigated, the grounds for the institute emergence were analyzed, and its discriminatory nature, causes and conditions of its assessment in the decisions of the US Supreme Court were revealed.