US Immigration Visas : Immigrant Visas
Employment Based
An immigrant is a foreign national who has been authorized to live and work permanently in the United States. If you want to become an immigrant based on the fact that you have a permanent employment opportunity in the United States, or if you are an employer that wants to sponsor someone for lawful permanent residency based on permanent employment in the United States, you must go through a complex process. The Immigration and Nationality Act allocates approximately 140,000 employment-based immigrant visas per year. Employment-based immigration is comprised of 5 preference categories, which are commonly referred to as EB-1 through EB-5. Each category has the statutory eligibility requirements.
Employment-based immigration generally requires either that a foreign national is one of the best in the field of endeavor or that there are no qualified US workers available to fill the position offered to the foreign worker. To obtain an employment based green card, applicants must be skilled/educated—and have a job offer. The process generally is three-fold:
(a) the employer must first obtain a "labor certification" from the U.S. Department of Labor (DOL) (showing that you will fill a position that the U.S. employer cannot fill with a U.S. worker)
(b) the employer applies for immigrant visa classification
(c) you then apply for lawful permanent residency in the U.S. embassy here in the U.K.
When applying for permanent immigration, you are saying to the government that you intend to work for your employer for the foreseeable future. You are not bound to the company for the rest of your life, nor is the company obligated to provide you with lifetime employment.