i am an fmg , and i am really new to the whole concept of usmle , and hence have a very rudimentary information level . 1 . could someone please tell me what prelim , transitional , and categorical programs are ? 2 . i at this stage am not sure of what field i wanna do my residency in , so is there a way for fmgs to work in a field for a shorter duration , maybe 6 months or a year ? what are the qualifying and visa requirements for such a program ? are such programs / jobs always formal , or can a profram director give me a job under him informally ? 3 . what is PGY1 , PGY2 etc ? - gurdesh .