To enter the United States, 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 United States permanently. Visas are obtained at a U.S. embassy or consulate abroad. Visas cannot be obtained within the United States because it is an "entry" document only.
People come to the United States 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 United States may be given an “F-1” or “J-1” student visa classification. A person coming to the United States for travel may be given a “B-2” visa, otherwise known as a tourist visa. The sample below shows what a tourist visa looks like:
What is the purpose of a visa?
A visa allows a nonimmigrant to travel to a U.S. port-of-entry (airport, for example) and present themselves to a U.S. Immigration Inspector. The Inspector will ask some questions about their intent for coming to the United States 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 United States with the visa that has their school's (or program's) 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 United States.
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 United States
Although a visa has an expiration date, it does not determine how long one can remain in the United States. (Remember, a visa is an ENTRY document only.) Once in the United States, there are other factors that determine the allowed length of stay. International visitors coming to the United States 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.