I ran into trouble with this...I'll try to tell you what I remember, but it's been a year since I was in this situation....
Evidently there's a box that you check off on your MCAT ticket or test itself that will allow your schools to be released to AAMC affiliated schools (I think there's a list of these schools somewhere)...they are primarily allopathic. If you want the scores sent to other schools that are not included (many osteopathic schools), you have to check off some other box and write in the name of the school. If you didn't do that, then you can go to the AAMC website and fill out the score release form (that's what I had to do). I think it costs around $10 or so.