To enter the U.S., all nonimmigrant international visitors (except Canadians) are required to have the proper visa stamp placed in their passports. “Nonimmigrant” means a person has no intention of staying in the U.S. permanently. Visas are obtained at a U.S. embassy or consulate abroad. Visas cannot be obtained within the U.S., because it is an "entry" document only.
People come to the U.S. for many different reasons. The type of visa you request should match the purpose for your visit. Visa types are classified using an alpha-numeric system. For example, a visitor coming to study in the U.S. may be given an “F-1” or “J-1” student visa classification. A person coming to the U.S. for travel may be given a “B-2” visa, otherwise known as a tourist visa. The sample here shows what a tourist visa looks like:
What is the purpose of the visa?
The visa allows a nonimmigrant to travel to a U.S. port-of-entry (airport, for example) and present themself to a U.S. Immigration Inspector. The Inspector will ask some questions about the intent of coming to the U.S. and check to make sure that the nonimmigrant has an appropriate visa. Once admitted, an I-94 Arrival/Departure Record will be created. This indicates which nonimmigrant status they have been admitted to and the amount of time they are allowed to stay.
A J-1 Exchange Visitor should only enter the U.S. with the visa that has the school's (or program) name noted on it (see annotation, above), even if the visa has not yet expired. If changing schools or programs, obtain a new visa with the new program name noted on it before entering or re-entering the U.S.
An F-1 student will also need to apply for a new visa if the SEVIS number on the I-20 has changed, regardless of whether or not a formerly issued F-1 visa has expired.
Visa Expiration and Length of Stay in the U.S.
Although a visa has an expiration date, it does not determine how long one can remain in the U.S. (a visa is an ENTRY document only). Once in the U.S., there are other factors that determine the allowed length of stay. International visitors coming to the U.S. as F-1 or J-1 students are generally allowed to remain for the length of their academic programs.
Applying For A Visa
For information about the steps involved in a visa application, see Applying For A Visa.