<p>The NIH funded MSTP programs, which pay tuition for a MD/PhD program, have their limitations. Competition is extremely intense. As one faculty member I know who has reviewed applications for these positions told me, the ones who succeed "walk on water". He sometimes could not believe they were for real.</p>
<p>The other downside is the service requirement. You didn't expect anything from DC to be free, did you?</p>
<p>If the OP is just starting college, the best (s)he could do is get some research experience to see if the life really appeals. There are many kids who are fascinated by the excitement of emerging science, only to find out the work itself is pretty tedious, not to mention isolating. That's one reason why NIH has to work pretty hard (funded MSTP, preference for MDs in research funding) to get some personality types involved in research.</p>