Far and few between unfortunately for PT. They are out there but usually are in less desired areas in the private sector. More desperate positions usually offer sign on bonuses if you stay for at least 2 years. Some government jobs and branches of the armed services have this possibility as well, though this is usually only offered to positions that they consider in demand at the time. You may consider the IHS (Indian Health Service), where a good chunk of money is paid towards your loans for every 2 years you work for them, though you likely won't get to choose where you're stationed.
