H1B portability provisions allows a nonimmigrant worker who was previously issued H-1B visa or otherwise accorded H-1B status to begin working for a new H-1B petitioner when the new employer files (USCIS must have received it) H-1B petition for the alien. The foreign worker must have been lawfully admitted into the U.S. Subsequent to such lawful admission; the foreign worker must not have been employed without authorization. The new employer must have filed a ‘non-frivolous’ petition while the foreign worker was in authorized period of stay.