An immigrant is a foreign national who has been authorized to live and work permanently in the United States. To become an immigrant through an employment opportunity in the United States, there is a multi-step process:

1. Most employment categories require that the U.S. employer complete the PERM Labor Certification process through the US Department of Labor (USDOL) to establish that there are no qualified, willing or able U.S. workers for the position and that the employer will pay an appropriate salary when the foreign national is granted permanent residence. There are categories that waive the labor certification requirement such as National Interest Waiver, Extraordinary Ability, Outstanding Professor of Researcher, etc.
2. USCIS must approve an immigrant visa petition (Form I-140) for the person wishing to immigrate to the United States.  Some applications require a permanent position and others do not.  Some require the employer to petition for permanent resident status, while other categories allow the individual to file without an employer sponsor.
3. The State Department must give the applicant an immigrant visa number, even if the applicant is already in the United States. When the applicant receives an immigrant visa number, it means that an immigrant visa has been assigned to the applicant. Sometimes, there is a long waitlist for an immigrant visa number to become available because there are too many people applying for immigrant visas in that category each year.
4. If the applicant is already in the United States, he or she must apply to adjust status to become a permanent resident (Form I-485 Adjustment of Status) once a visa number becomes available.  If the applicant is outside the United States when an immigrant visa number becomes available, he or she will be notified and must complete the process at a U.S. consulate office abroad.

The United States allows approximately 140,000 immigrants each year to be granted permanent residence through their intended employment in the U.S.