Visas & Travel for J-1 Students
A visa is like a "ticket of admission." You apply for it outside the U.S. and need it to enter the U.S. Your visa type, expiration date, issuing office, and the number of entries permitted will be stamped in your passport. You may stay in the U. S. even if your visa has expired, but you may not leave and then re-enter if your visa has expired. (An exception occurs if you are returning from an adjacent country, e.g., Canada or Mexico, after a stay of less than 30 days, and you may then be eligible for an automatic extension at the border.)
If you are a J-1 student, you have been admitted for "Duration of Status" which means that you may stay in the U. S. as long as you are a regularly registered, full-time student. Different visas have different advantages and restrictions. Check with the International Student Center for information regarding your visa.
Travel Outside the U.S. And Re-Admission
If you have a J-1 visa, for reentry you will need your passport with a current visa stamp showing that multiple entries are permitted, and a DS-2019 form endorsed by the International Student Center. Please do not misplace your DS-2019 forms.
You will also need a passport that is valid for at least six months.
It is also recommended to bring your letter of admission, a recent I-94 and proof you are registered for the upcoming term if possible. After you have returned make sure to check your I-94 that you entered under the right status.