For immigration involving US companies and specialty workers, the visas required are the H1B and L1. The H1B visa allows a US based firm to employ foreign specialty occupation workers for a maximum of six years. The L1 visa permits a company that is both operating within the USA and abroad, to transfer a particular class of worker from its foreign operation to the USA, for a maximum of seven years.
For non-US firms and potential investors in the USA, B1 and B2 visas and E1, E2 and E3 visas are the ones to apply for. B1 and B2 visas or visitor visas, are only valid for a planned business trip, but not for gainful employment or running a business. Foreign nationals of treaty countries, who carry on a substantial volume of international trade with the USA, may be granted an E1 visa. Foreign nationals of qualifying treaty countries who have made a substantial investment in the USA may also qualify for an E2 visa. The E-3 visa, however, is specifically designed for Australian nationals who wish to enter the USA to perform services in a “specialty occupation.”
For a foreign individual who wishes to gain residency and work authorisation in the USA, sponsorship by an employer, investment, sponsorship by a close relative already residing in the country, the annual Diversity Visa Lottery Programme and asylum and refugee status, are the five main possibilities.
For exchange visitors, a visa gained under the J-1 Exchange Visitor Programme permits a foreign individual to train, work and travel within the USA.