Visa for Specialized Knowledge Worker L-1B Visa This visa (in the U.S., L-1B visa) is designed for foreign workers with specialized knowledge related to the field, products, or processes of their destination-country-based employer (e.g., U.S.-based employer). In the United States, this non-immigrant visa allows these specialized knowledge employees to be transferred from a foreign office to a U.S. office within the same company for up to five years.