Switching Tracks Once Accepted

If you're accepted to a certain track program, are you able to switch once admitted into medical school? Some of the programs are focused on a specific specialty. Of course, I'm willing to give it a try and hopefully all works out. However, if I'm not happy going into that field of medicine after giving things a serious try, would I have the opportunity to switch tracks while in school, or will admittance typically be for only that particular program and I can consider myself stuck for good?
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Source Type: forums