United States Citizenship & Immigration Services is the agency within the Department of Homeland Security that regulates and monitors immigrant labor. Although immigrants may enter the United States under a variety of statuses, the ability to accept employment is restricted to just a few forms. Specifically, two categories of documentation that USCIS validates are the employment authorization card and work visa. Each document provides unique privileges.
Employment Authorization Cards
Foreign nationals in the United States who are eligible for employment may file Form I-765 with USCIS. Typically, employment authorization cards are requested by foreign students or pending I-485 green card applicants. Unlike a work visa, employment authorization cards are not tied to a specific employer or position. This gives holders the freedom to pursue multiple employment opportunities. However, employment authorization cards only carry validity for one year before they require renewal.
Under some work visas, such as the popular H-1B visa, a dependent spouse may accompany the work visa holders to the United States, but are not eligible for employment. However, once an H-1B visa holder applies for a green card (I-485), both the visa holder, the spouse and any eligible children are able to file I-765 application to receive an employment authorization card. Once the green card is approved, the employment authorization cards are no longer needed to accept offers of employment.
Temporary Work Visas
Temporary work visas are available in numerous categories. The most popular visas are H-1B specialty occupation and L-1 intracompany transfer visas. H-1B visas require a foreign national to possess a bachelor's degree or its equivalent in a field related to the offer of employment. L-1 visas allow companies with foreign affiliates or parent companies to transfer employees to the United States for projects that require specialized knowledge or the aid of an executive manager. H-1B visas initially include a three-year period of employment, with the opportunity to renew the visa for an additional three-year period. L-1 visas also have a three-year initial period of employment, followed by an opportunity to renew the visa in two-year increments for a total of seven years.
Permanent Work Visas
Permanent work visas are employment-based green cards. Unlike temporary work visas that request the services of an employee for only a short period of time, employment-based green cards are offered when a position is expected to be permanent in nature. Green cards themselves must be renewed every 10 years, but are indefinitely renewable. Except in rare cases of individuals with extraordinary abilities, such as musicians, artists, scientists, doctors, athletes, etc., employment-based green cards require the sponsorship of an employer. USCIS requires that the sponsor complete a tedious and lengthy recruitment process, which may take several years to complete.