Do you have to do a fellowship directly after residency, or can you work for a while and go back? Is it more difficult to get into a fellowship if you don't apply directly after residency? I am thinking about the HPSP program, which requires 4 years of active duty after residency. I am wondering if it is possible to do an internal med residency, complete my HPSP commitment, and then apply to a civilian fellowship once I am out of the military. Thanks!