You probably need waiver: an example

Depends on what country do you reside.
http://www.hooyou.com/j-1/j1_limitation.html

Jeff is a Chinese national and his current country of permanent residence is Hungry. While in Germany as a visiting student, he obtains a J-1 visa to come to the U.S. to study Economics. Upon completion of his studies, he must fulfill his two-year foreign residency requirement in Hungry, since that was the country he resided in when he obtained his J-1 waiver.