Yes, a job offer from a U.S. employer is a basic requirement for the O-1 Visa. The applicant must be coming to the U.S. to work or perform at an event or a series of events in the area of extraordinary ability. The term “event” is interpreted liberally, outside the fields of athletics and arts, and can include, for example, an ongoing research project for a private company. A USCIS approval authorizes the individual to work only in the position and at the company specified in the petition. An O-1 Visa holder may work for more than one employer, but each employer must file a separate visa petition.