Here is the website, http://nhsc.bhpr.hrsa.gov/
I looked into it and it seems like a really good experience. You have to want to go into primary care and I think they actually accept more people who come from underserved areas simply bc they have more vested interest to return to those areas. The last thing they want to do is pay for someone's med school and have them burn them. They get their money back, plus interest, but still it is supposed to be pretty competitive. I am not sure what I want to specialize in but if I got the way of primary care I may look into it. I think you can still apply after the second year and it may be a great way to defer costs. Oh and I think it is similar to the military in that you give back a year for a year they pay, not including residency but I am not 100% on that.
-ct