Returning to the same program sponsor
In order to avoid problems re-entering the country, consult with your program sponsor before you leave the U.S. You will need to have your DS-2019 signed and may also need a letter verifying your status as a J-1 scholar. You may also need to obtain a new U.S. visa.
Returning to a different program sponsor
You must consult in advance with your current program sponsor about your proposed travel and transfer to a new program sponsor. Your program sponsor will be able to alert you to possible problems you may encounter. If the change is permissible, you must obtain a new Form DS-2019 from the new program sponsor to which you will transfer before you attempt to re-enter the U.S.
Documents needed when entering it the U.S.:
Valid visa (Canadians are exempt from the visa requirement)