The O-1 category is set aside for the principal alien with extraordinary ability. The law establishes three different standards for the O-1 category:

1. the most exacting standard applies to aliens in the sciences, education, business, and athletics;
2. a much less rigorous standard applies to individual aliens in the arts; and
3. an intermediate standard applies to aliens of extraordinary achievement in the motion picture or TV industries.

The O-2 category is set aside for aliens who will accompany and assist in the artistic or athletic performance of an O-1 alien and aliens who will accompany and assist an O-1 alien on a specific motion picture or television production. O-2 aliens must have a foreign residence which they have no intention of abandoning; this requirement, which was eliminated for the H-1B category, is not imposed for O-1 aliens.