Each time you travel outside of the United States you will need the following documents to re-enter:
Your I-20 with a travel signature less than six months old
Travel Signatures can be found on page two of your I-20.
Valid F-1 Visa
If your visa is expired, you will need to apply to renew it at a U.S. embassy or consulate in your country. You should contact your local embassy or consulate immediately to learn how long the process may take, and plan your travel dates accordingly.
Valid at least six months into the future
Financial Documents indicating your available funds (recommended)
Current Transcript or letter confirming continued enrollment (recommended)
All previous I-20s (recommended)
Photocopies of documents: Be sure to make at least two copies of all of your important documents (I-20s, visa, I-94 card and the main page of your passport) so that you can replace them more easily if they are lost or stolen. We recommend that you keep one set of copies in your carry-on luggage and another set at home with someone who can send them to you if needed.
Students on Optional Practical Training (OPT)
If you are currently on OPT, you should travel with the items above plus your valid EAD card and a letter from your employer, on company letterhead, stating that you have been employed and will return on a specific date to resume employment. (If your employer authorizes your leave, the travel time will not count toward your days of unemployment.) Note that it may be somewhat riskier to travel (particularly if you need to renew your visa) in the last six months, and especially the last three months, of OPT.
F-1 Students on Study Abroad
Make sure to carry all of your documents with you for when you return to the United States and to get a new travel signature before you go abroad. You will also need to check with the country you are studying in if you will need a visa to study there. The Office of International Education only advises on U.S. visas; you will need to do independent research on any other country’s visa you may need.