This is for all opt and stem opt student who is confused of travelling out of US. I just got in after my vacation . I am on opt and i was out of country for couple of weeks. I traveled through China and NYC. The journey is pretty fine, NO issues and nothing. Even Nepali and Chinese Immigration officer didn't ask for I-20, (just passport). In POE which is NYC, the officer just ask for I-20 and passport,no any question. I gave my i-20 and passport, the officer just stamp it and told me good-luck.. Please feel free to travel and live your dream.