One path to become a lawful permanent resident is through employment. If you have a permanent job in the United States, although "permanent" doesn't mean it has to be "forever," you and your employer must complete a multi-step process to obtain a green card:
There are five major categories under EB immigration and each one has its own subcategories. See more details below. To make a decision, you not only have to consider your own qualifications, but also the job requirements, overall job market, visa retrogression, and so on. You may be eligible for two or more categories and decide to go with a lower preference, or start two processes in parallel.
The category you choose is critical when it comes to the final stage of green card application: immigrant visa number availability is regulated based on EB preferences and may be more limited for one category than another.
In most cases you will need an approved labor certificate to move on, which can become time consuming with advertising, recruiting, processing, potential auditing, etc. The LC process (currently named PERM) is conducted by the Department of Labor's Employment and Training Administration (ETA).
Your EB category is not defined in the LC stage. But the job description and requirement on your LC application will have an impact on your category in the I-140 phase, for example, EB2 vs. EB3.
Certain qualified applicants are relieved from the LC requirement, including EB1 and EB2 NIW.
An approved I-140 means the beneficiary is now eligible to obtain an immigrant visa number. I-140 is filed by your employer, and is the property of your employer, unless you are qualified for self petition. If labor certification is required, I-140 can only be filed after the certification has been granted. Your EB preference will be determined in this step as well.
If your LC has been approved, and your priority date is current, you may be able to file I-140 and I-485 concurrently. This means you can combine 3 and 4 in one step, but your I-140 still must be approved before I-485 can be processed.
Note that special immigrants such as religious workers and physicians need to submit I-360 instead of I-140.
You may file I-485 to adjust your status to that of an immigrant (if you are already in the U.S.), or go through Consular Processing (if you are outside the U.S.). After this step you will receive your green card, and become a permanent resident.
However, before you can start step 4, there must be an immigrant visa number available to you. Visa numbers are administered by the Department of State, and released once a month in the Visa Bulletin. You will notice that visa number availability is different for different EB categories. If your priority date (the date you file LC, or I-140 if LC is not required) is within the visa bulletin cut-off dates, you can then start step 4. This is why it is so important to start your process early, and choose your preference carefully.
After you submit an I-485, visa number cutoff dates may move further back (retrogression gets worse). In this case you must wait for your priority date (PD) to become current again before your I-485 can be adjudicated. Somewhere before your green card's approval, you must come out clean during various USCIS security checks, including FBI name checks.
There are five employment-based categories: