You should have a valid photo I.D. with you at all times. Your student I.D. card will generally be sufficient.
Keep your passport and immigration documents in a safe place. When traveling by airplane within the United States you should bring your immigration documents unless you have a state identification card.
If you are traveling outside the U.S. to re-enter you must have:
Traveling with documents such as school I.D., class registration, etc. are suggested, but not required.
Make sure you have your I-20 signed within one (1) year of your plans on returning if traveling outside the United States. More information is available at Travel.State.Gov.
Please look at your I-20 to make sure that it is not going to expire.
If you think your I-20 is expiring and you are not going to graduate, please make an appointment to meet with the International Student Advisor as soon as possible.
Traveling and the I-20