A person seeking to become a permanent U.S. citizen should obtain an immigrant visa. Most immigrants receive visas in the family-based or employment-based visa categories. Coming to this country based on family often requires a U.S. citizen to file an immigrant visa petition for a spouse, child, parent, or sibling. Another route is that a U.S. lawful permanent resident (i.e., green card holder) can file an immigrant petition for a spouse or an unmarried son or daughter. Employment-based immigration involves a U.S. citizen sponsoring certain workers for permanent jobs. U.S. law also permits prospective immigrants to sponsor themselves in limited fields. Additionally, U.S. law provides many specific immigrant categories, including an investor visa.