There are a wide range of temporary (i.e. nonimmigrant) visas issued for many different purposes. The visas may last from a few days to several years. Some must be approved in advance by the U.S. Citizenship & Immigration Services (USCIS) before being reviewed and issued by the U.S. Department of State (DOS); others are reviewed only by DOS. In many nonimmigrant visa categories, visas are made available not only to the principal applicant, but also to the visa holder's spouse and/or minor children.

NOTE: There is a difference between a “visa” and “status,” although both are referred to in the same general way and with the same alphabetical denomination (which is based on the section of the Immigration and Nationality Act in which the category is defined). A visa is a document placed in a person’s passport by DOS, which enables a person to apply for admission into the U.S. for a particular purpose. A person's status is granted when s/he is admitted into the U.S. Status is initially granted at the port of entry, and, after an individual is admitted to the U.S., often can be changed or extended by the appropriate USCIS Regional Service Center.

The following is a list of many of the categories of nonimmigrant visas:

A: Diplomatic employees (A-1), foreign government officials (A-2) & their personal employees (A-3) *

B: Visitors for business (B-1) or for pleasure (B-2)

C: Transit visa (pass-through at an airport or seaport)

D: Crewmembers (air or sea)

E: Treaty Traders (E-1), Treaty Investors (E-2) or Australian professionals (E-3) *

F: Students (F-1) *

G: Employees of International Organizations (e.g. IMF, OAS, UN, International Red Cross, etc.) *

H: Temporary Workers, including professionals (H-1B), Free Trade professionals from Chile or Singapore (H-1B1), nurses (H-1C), agricultural workers(H-2A), temporary or seasonal workers (H-2B), or trainees (H-3) *

I: Representatives of international media *

J: Exchange visitors (e.g., educational exchange students, au pairs, graduate medical trainees, students, professors and researchers, short-term scholars, camp counselors) *

K: Fiancés and fiancées of U.S. citizens (K-1) or children thereof (K-2), and spouses of U.S. citizens (K-3) or children thereof (K-4)

L: Intracompany transferees, including executives or managers (L-1A), or persons with specialized knowledge (L-1B) *

M: Language and vocational students *

N: Parents/Children of SK Special Immigrants

O: Individuals of extraordinary ability in sciences, arts, education, business or athletics (O-1), support personnel (O-2) *

P: Athletes & entertainment groups (e.g. orchestras) and support personnel *

Q: Participants in international cultural exchange programs (e.g. Smithsonian Folklife Festival)

R: Religious Workers *

S: Certain individuals supplying critical information relating to criminal organization or terrorism *

TN: Individuals from Canada or Mexico who are permitted to enter under the North American Free Trade Agreement (NAFTA) *

T: Victims of Trafficking in persons *

U: Victims of crime who have suffered abuse and are cooperating with the U.S. government in investigation or prosecution of the crime *

WB: Visa Waiver entrants for business

WT: Visa waiver entrants for pleasure

* Dependent visas are also available for these categories to allow spouses and minor children to accompany the primary visa holder