Getting US work visa and planning to live there is an important decision. Generally, a foreign applicant seeking a work visa must be sponsored by a permanent residence or an employer. While applying for a work visa in US, a petition must be filed with U.S. Citizenship and Immigration Services (USCIS) by an applicant. Work Visas in U.S may vary by category and depend on the manner in which you are planning to work in U.S. The primary categories are as follows: