U.S. Citizenship and Immigration Services

U.S. Citizenship and Immigration Services handles the paperwork side of the immigration system: who can enter the country temporarily, who can work here, who can study here, and who can eventually become a citizen. It sits inside the Department of Homeland Security and processes the visa and status applications that determine what a foreign national is legally allowed to do while in the United States.

Temporary visits make up a large share of the system, covering everyone from tourists and business travelers to diplomats and journalists passing through the country. Categories like the U.S. Tourist Visa (B-2 Visa) and the B-1 Business Visitor Visa spell out how long someone can stay and what activities are actually permitted, since each visa type is built around a narrow purpose.

Work authorization is one of the more contested areas, because it connects directly to the labor market. Programs range from seasonal farm labor under the H-2A Visa for Foreign Agricultural Workers to specialized professional roles under the H-1B Visa Program, corporate transfers through the L-1 Visa for Transfer Employees to the United States, and short-term hiring covered by the H-2B Visa for Temporary Foreign Workers. Employers also carry their own obligations, including the Employment Eligibility Verification process required for every new hire.

Study and exchange programs let people come for education or cultural exchange rather than employment, such as the F-1 Student Visa and the J-1 Visa for the U.S. Exchange Visitor Program, each with its own rules about how much work, if any, a participant can take on alongside their studies.