I also added UM later (two months after I submitted the AMCAS). They sent me the secondary app link that afternoon (Oh, I paid the $30 to AAMC at around 8am), and it already listed an interview request (I called them and emailed them to make sure it wasn't a mistake, but it turns out they also invite for interviews purely based on numbers).
Just in case they do not process your request this weekend, here are the essay prompts (I'm pretty sure they're the same for everyone):
1) Select one experience from your list in part B (Non-Academic Activities) and describe in a brief essay how it impacted on your decision to go into medicine. Do not exceed 1500 characters (about 250 words).
MSTP applicants: Instead of the above, briefly describe why you decided to apply to the U of Michigan MSTP. If you are interested in a specific department, program, or area of research for your Ph.D., briefly explain (we recognize that your interests may change).
2) At the University of Michigan Medical School, we are committed to building a superb educational community with students of diverse talents, experiences, opinions, and backgrounds. What would you as an individual bring to our medical school community? Do not exceed 1500 characters (about 250 words).
