This requires an employer to "sponsor" (petition) the immigrant (known as the "alien beneficiary") through a presumed future job. If a successful application is made, the alien is expected to take the certified job offered by the employer.

How To Apply for an Employment-based Visa

Labor Certification

The first step is establishing the Labor Certification. The employer must legally prove that it has a need to hire an alien for a specific position and that there is no minimally qualified U.S. citizen available to fill that position.

Requirements:
• Proof of advertising for the specific position
• Skill requirements particular to the job
• Verification of the prevailing wage for a position
• Employer's ability to pay

This step is processed by the United States Department of Labor (DOL). This application is completed through an electronic system known as PERM. The date when the labor certification application is filed becomes the applicant's priority date. The labor certification is valid for 6 months from the time it is approved.

For highly skilled foreign nationals (EB1 and EB2 National Interest Waiver, e.g. researchers, athletes, artists or business executives) and "Schedule A" labors (nurses and physical therapists), this step is waived.

Immigrant Petition

An Immigrant Petition is the next step. An employer applies on the alien's behalf to obtain a visa number. The application is form I-140, Immigrant Petition for Alien Worker. It is processed by the US Citizenship and Immigration Services (USCIS).

There are several EB (employment-based) immigrant categories like EB1-EA, EB2-NIW, EB5. Many of the applications are processed under the EB3 category. This process takes up to 6 months.

Immigrant Visa Availability

When the immigrant petition is approved, the petition is forwarded to the National Visa Center (NVC) for visa allocation. The visa becomes available when the applicant's priority date is earlier than the cutoff date announced on the DOS Visa Bulletin or when the immigrant visa category the applicant is assigned to is announced as "current". When the NVC determines that a visa number could be available for a particular immigrant petition, a visa is tentatively allocated to the applicant. The NVC will send a letter stating that the applicant may be eligible for adjustment of status, and requiring the applicant to choose either to adjust status with the USCIS directly, or apply at the U.S. consulate abroad.

Immigrant Visa Adjudication

When the NVC determines that an immigrant visa is available, the case can be adjudicated. If the alien is already in the USA, that alien has a choice to finalize the green card process via adjustment of status in the USA, or via consular processing abroad.

If the alien is outside of the USA, they may apply for an immigrant visa at the U.S. consulate.

The applicant must have a medical examination performed by a USCIS-approved civil surgeon. The examination includes a blood test and specific immunizations, unless the applicant provides proof that the required immunizations were already done elsewhere. The civil surgeon hands the applicant a sealed envelope containing a completed form I-693.

The final step is to change his or her status to permanent residency. Adjustment of status is submitted to USCIS via form I-485, Application to Register Permanent Residence or Adjust Status.

Official Site

Green Card through a Job Offer