Sign on bonus, AKA Forgivable Loan?

One of the Full time job offers that I am considering has a sign on bonus that is tied to the job for 4 years. The recruiter tells me it is a forgivable loan that means if I work for 4 years with that company, I will not have to repay the sign on bonus. No moving expenses. What happens if I quit before the full 4 years? Will that be taxed as ordinary income? Can I offset my closing costs on real estate from that forgivable Loan Any other tax implications that I am missing out? Thanks
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Tags: Anesthesiology Source Type: forums