Be prepared to talk about your AMCAS experiences more in depth, and really be able to articulate why you want to practice MILITARY medicine specifically. My interview, and from what I've heard most of the interviews, are very conversational and open ended. For me, the questions were very open, for instance "You are aware that the USU incurs a lengthy service commitment. Are you and your family prepared for this?" and "I see you listed *such and such* on your application, how has that molded your leadership style?". Ask your interviewers questions too! More than half of my interview time was spent asking them questions about their research and experience in military medicine. It really shows that you are interested and invested in practicing this very specific brand of medicine. Just be YOU, and have fun with the interview. You'll do great!