Have you looked on the IHS website?
Why do you want to work for the IHS?
I took an IHS scholarship and worked for them for 4 years. WORST experience ever. It ruined me financially, made me hate nursing and broke my spirit. It's a backward and corrupt government agency that runs an archaic health care system that is underfunded, outmoded, and mostly exists in extremely poverty-stricken rural areas. The jobs are low pay, high stress and very, very depressing and understaffed.
Keep in mind they practice preference of hiring Native candidates first. And they have a ready-made pool of candidates from the scholarship obligation program they are required to hire from by law.
I cannot imagine why anyone would want to work for this agency unless they are obligated to by contract. If you are a non-Native person who just wants to "help the poor Indians" you won't last 5 minutes in an interview or on one of these reservations. Trust me on that.