The United States Biology Olympiad (USABO) is a highly competitive biology competition for high school students in the United States. It is designed to stimulate young scholars' interest and excellence in the field of biology and identify the most talented biology students.

https://www.usabo-trc.org/

The USMDO, the US Medicine and Disease Olympiad, is America’s qualifying competition for the IMDO, the International Medicine and Disease Olympiad. The first USMDO was held in 2022 and qualified 8 students for the 2022 IMDO, almost all of whom won gold medals at the international competition. The second annual USMDO will take place on Saturday, 7/29/2023.

https://www.usmdo.org/

The United States of America Computing Olympiad (USACO) is a prestigious programming competition for high school students in the United States. It is designed to identify and nurture talented individuals in the field of computer science and programming. 

http://www.usaco.org/index.php

The National Economics Challenge is an annual competition in the United States that focuses on testing high school students' knowledge of economics. It is organized by the Council for Economic Education (CEE) with the aim of promoting economic literacy and encouraging students to develop a strong understanding of economic principles. 

https://www.councilforeconed.org/programs/for-students/national-economic-challenge/