Professionals can apply for a variety of nonimmigrant visas including an H-1B Temporary Worker, L-1A Intra-company Executive or Manager, L-1B Specialized Worker, TN Worker (for Canadians or Mexicans), O Extraordinary Ability Workers, and in some cases, E executive or essential worker visas. Most non-immigrant visas require a U.S. employer to file a petition with USCIS for the benefit of the foreign national worker.