For more than 30 years, NCEE has made it a priority to identify and learn from the highest performing school systems in the United States and around the world to uncover valuable lessons and insights for education systems aiming to boost their performance and student outcomes. The Department of Defense Education Activity (DoDEA) serves children of military families both in the United States and overseas. In recent years, DoDEA students have consistently outperformed their peers in other states on the National Assessment of Educational Progress (NAEP)--and they do so by wide margins. DoDEA has also showed the most progress in closing longstanding achievement gaps between White students and their Black and Hispanic classmates; and it was the only school system to see its scores hold steady, and even rise somewhat, during the COVID-19 pandemic. This case study, written by Raphael Heller--former editor-in-chief of Phi Delta Kappan magazine with more than 30 years of experience as an educator himself--explores DoDEA's unique, high-performing education system including its structure, governance, curriculum standards, and assessment methods. It also looks at other factors that might influence these high performance levels, such as the disciplined military culture and the strong support systems for students and families.