A company is able to keep a temporary employee for up to one year as of 2015, according to the U.S. Department of Labor. These appointments, when begun, must have a specific end date in order to qualify.
The use of temporary employees is appropriate when a business has need of an employee or employees to complete a short-term task. They are also used when a company has a specific time of higher volume, or if a company is seasonal. Temporary employees are able to earn paid leave and do qualify for Social Security. However, they are usually not eligible for any of the additional benefits typically offered to full-time employees.