Hi,
I am a French Canadian and I have worked under a J-1 visa as a teacher for 2 years in the USA (august 2006 to July 2008). I know for sure that as a Canadian, I had to pay my Federal taxes but recently, my employer from the USA contacted me to tell me that I should be exempted from the FICA taxes but they are not sure about the medicare taxes. They asked me to do some research on my side to speed the process. I have always made my taxes report while I was there in both countries so I am a little bit confuse about all this. Can you help me to understand.
Best reagards,
lolag

Every one on J-1 is exempt from residency for 2 years. You income is not subject to SS tax and Medicare tax. You must file nonresident tax return and Form 8843. Your U.S. Tax Return: U.S. Tax Filing Requirements for Non-Residents
You will pay federal and state income taxes.