Family members of the H-1B foreign worker are admitted to the United States in the H-4 category. Qualifying family members include only the spouse and unmarried children under 21 years old. H-4 dependents are admitted for the same period of time for which the H-1B foreign worker is admitted. H-4 dependents may alternatively be admitted in other nonimmigrant categories for which they qualify. H-4 dependents may undertake studies while remaining in the H-4 category, however, they may not engage in any form of employment.