Yes you can work till your OPT expires....but once your OPT expires you can not work... if you are a STEM student, you can get an extension for 17 months but if you are not eligible for extension, only way to continue working for the current company is to get a CPT from the college you are enrolled in. There is no way you can continue working on OPT after it expires. I've worked on OPT (29months) and on H1B.... so i'm telling you from my experience.