The most common way that people legally immigrate to the US is through family based immigrant visa petitions.  Adult US citizens may petition or “sponsor” their spouses, parents, children and siblings.  Lawful permanent residents of the United States may petition their spouses, minor children and adult unmarried children.   In all cases documents establishing the familial relationship must accompany the visa petition which is filed with USCIS in the United States. 

In the case of immediate relatives of US citizens (spouses, parents and unmarried minor children) the petitioner and family member may also file a one-step application for adjustment of status for their relative who are in the US after a lawful admission (See Adjustment of Status).  Others await the approval of their visa petitions and often must also wait for the visa petition priority date to become current so their relatives can seek an immigrant visa at a US consulate in the relative’s home country.

The process of seeking an immigrant visa at a US Embassy outside of the US is completed through the National Visa Center, a part of the US Department of State.   For more information on visa processing see the section on “World-wide Visa Processing” or visit the National Visa Center website at http://travel.state.gov/visa/immigrants/types/types_1309.html.