The USA Physics Olympiad (USAPhO) is a highly competitive, multi-stage physics competition for high school students, organized by the American Association of Physics Teachers (AAPT). The program serves as the selection process for the U.S. Physics Team, identifying top students to represent the United States at the International Physics Olympiad (IPhO) based on their mastery of conceptual and mathematical physics.

Students first qualify through the F=ma exam, a 75-minute multiple-choice test focusing exclusively on classical mechanics. Approximately the top 400–500 scorers are invited to sit for the USAPhO, a rigorous free-response exam that covers the full breadth of introductory physics, including electromagnetism, thermodynamics, relativity, and nuclear physics.

https://aapt.org/physicsteam/PT-landing.cfm