Are you talking IHS? You get $25k or so which comes out to a little over $18k after taxes. You can do that every year until your loans are paid off.
Are you talking PSLF or some other program where you work at non-profit or govt hospitals? That is quite variable... need to make sure you qualify (type of loans, employer tax status, etc), make sure you stay there the proper timespan, and make sure that it gets approved (far too many fall through at the end). It would honestly be worth an attorney or other specialist consult; it would suck to do 7 or even 10yrs at a place you basically picked for forgiveness potential... only to have it bounced. Also, the consensus with a lot of MDs is that you can do better making more in private group/hosp than trying for PSLF jobs... for DPMs, who knows?