I am a doctor on J-1(doing my fellowship) from India. I was told that I was exempt from Taxes as long as I am on J-1. Can some one please let me know how long am I exempt from taxes and file for my taxes to be returned back to me?

Normally, a J-1 exemption lasts two years.

However, if you stay past two years or you change your status, then you are you are subject to all taxes retroactive to the date you entered the U.S.