Explicitly excluded from the H-1B category are persons who qualify for O or P nonimmigrant status. Such individuals include all athletes, entertainers, and artists. The O category also covers persons with extraordinary ability in the sciences, education, and business. Technically, therefore, such persons may only qualify in the O category and not the H-1B category, even though they may have the credentials to be considered professionals and may be working in specialty occupations. USCIS, however, generally does not deny H-1B cases for workers in specialty occupations on the grounds that they are overqualified for the H-1B category because of their extraordinary ability.

Until September 1, 1995, professional nurses were also explicitly excluded from the H-1B category. Such nurses needed to qualify for a nonimmigrant visa in the H-1A category. Authorization for that category was limited to a five-year period that expired on August 31, 1995. Nurses may qualify for H-1B status provided the nursing position involved is an H-1B caliber position.