Before Traveling Abroad
If you plan on traveling outside the U.S. during your studies, you must have your I-20 or DS-2019 signed by your International Student Advisor before you leave. The advisor's travel signature is only valid for six months.
If you do not have a current signature on your I-20 or DS-2019, you will have difficulty re-entering the U.S. You should visit your advisor's office with your passport that has a valid F-1 visa stamp and I-20 or DS-2019, at least two-three weeks before traveling.
Also, make sure that your passport is valid for at least six months from the day you plan to re-enter the U.S. You cannot enter the U.S. on the F-1 or J-1 visa, using a passport that is less than six months from expiration.
You will always need to maintain a valid F or J Visa in order to re-enter the U.S. Check the expiration date on your visa to see when you will need to renew it. Remember, you can only renew it at the U.S. Consulate in your home country. You can not obtain or renew the visa in the U.S. Know that if you visa expires while you are in the U.S., you do not have to renew it until you leave the U.S. for a vacation in your home country.
If you have a valid visa in an expired passport, always present both, the old and new passport to the U.S. Customs and Border Protection Officer.