If you plan on leaving the U.S. temporarily to visit your homeland or some other country, a DSO/ International Student Advisor must validate your I-20 for re-entry into the U.S. Allow at least one week before your departure to obtain a DSO/International Student Advisor signature. You may not be allowed back into the U.S. without the validated immigration documents, a current visa, and a passport which is valid for at least six months after you re-enter the country.
Most students with valid status may travel to Canada, Mexico and many of the adjacent islands if they have a valid passport, a valid I-94 and a valid I-20 or DS-2019. If you re-enter the U.S. in fewer than 30 days, an unexpired U.S. visa is not required. However, Canada, Mexico and the Island nations do require entry visas for citizens of certain countries.
It is always best to check with the embassy or consulate of any country you wish to visit. Since certain countries are ineligible for this benefit and travel regulations are subject to change, you should check with the International Student Advisor if you intend to travel with an expired visa.
Students who apply for a new visa in contiguous territory forfeit the right to re-enter with an expired visa. If the new visa is denied, the student would not be able to re-enter the United States to study until a valid visa is obtained in their home country.