The process to get a green card through employment is long and complex. It is more than just a promotion or change of positions. Yes, your employer can sponsor you, however, they must go through this process. When filing a green card, immigrants and their sponsor (in this case employer) are required to submit several forms. For the employer based green card, you should be prepared to submit form 1u2013140, form 1u2013485, and the Permanent Labor Certification (PERM)Permanent Labor Certification (PERM) process -The majority of employer-based green card are done though the PERM process. PERM is a certification where an employer shows that they have made an effort to hire a qualified US citizen before hiring an immigrant. In order to show evidence of this, employers must implement an advertising campaign for its job opportunity. They must then show that no qualified US citizen applied for the position. They must do this before starting any part of the green card application.I-140 - Immigrant Petition for Alien Work - This form is a document that is used by an employer to petition for an immigrant worker to come to the United States.I-485 - Affidavit of Support - Through this form an employer accepts financial responsibility for the immigrant worker. According to the USCIS, you should be prepared to submit the following documents as supporting evidence for the I-485:Evidence of admission into the United States (Form I-94, Arrival Departure Record)If your I-140 has been approved, pra copy of the approval notice sent to you by the USCISJob offer letter from your employerTwo color photos taken within 30 daysForm G-325A, Biographic Data SheetForm I-693, Medical ExaminationFor more info on required supporting evidence, check out this page.Best of luck!