• B-1: Business visa, usually valid for six months or less, but may be extended
• E: Treaty trader or investor visa
• F-1: Student visa
• H-1: Professional visa, with the right to work for sponsoring company, valid for up to 7 years.? Usually requires a degree
• L-1: Intra-company transferee, sponsored by a company abroad with a related company here, providing the right to work for the sponsoring company
• O/P: Artist or entertainer

  Persons obtaining these visas are permitted to enter the United States for temporary, specifically defined periods of time and in most cases must show intent to return to their home country at the end of their temporary stay.
  Those applying overseas have their eligibity reviewed twice before coming to the United States. The State Department Consular Officer decides whether the individual's purpose in coming fits one of the approved categories, and whether the person meets all other eligibility criteria for admission before issuing a visa to allow the individual to come to the United States. Upon arrival, all nonimmigrants are inspected by the INS to reconfirm their qualification for admission, and to authorize a specific length of stay. This process at the border has become more difficult in the past several years, as border officials aggressively scrutinize a person's reasons for coming here before admitting them.