Elementary and secondary science, technology, engineering, and mathematics (STEM) education is the foundation for students' entry into postsecondary STEM majors as well as a wide variety of STEM occupations. Proficiency in STEM fields is vital to economic growth and international competitiveness and important for all citizens in an increasingly technology-driven society. A skilled and diverse STEM workforce is essential for the United States to remain preeminent in science and engineering (S&E) and continue to be at the forefront of innovation. Improving K-12 STEM education and nurturing the talents of all Americans--including women and underrepresented minorities in STEM--is key to maintaining U.S. competitiveness and strengthening and diversifying its STEM workforce. An increasingly complex technological society and such events as the COVID-19 pandemic underscore the important role that K-12 STEM education has to play in building public understanding of science and creating a scientifically literate citizenry. This report provides the most recent available indicators of the state of U.S. K-12 STEM education. It presents data about student performance in mathematics in fourth and eighth grades; computer science performance in eighth grade; U.S. mathematics, science, and computer science performance compared with that of other nations; U.S. mathematics and science teachers' qualifications and how they compare internationally; and high school students' preparation for postsecondary education and the workforce. [SRI International, Center for Innovation Strategy and Policy, assisted with report preparation.]