You have filed I485 and are now thinking of all future questions of job change or layoff and their effects on Green Card.Then this is the right post for you.
What is AC21 law ? The AC21 law provides in general that one who has an approved I140 petition and I485 pending at least 180 days and accepts new permanent employment will still be eligible for adjustment if the new job is in the same or similar occupational category as the original job offer.One who is accepting new employment under the green card portability rules of the AC21 law and wishes to notify USCIS about the basis for one’s continuing eligibility to adjust status is generally able to satisfy the notice request of USCIS by providing a letter with the details of the new job and the start date.
The big question though is of “received date” or “notice date” that is taken into consideration for AC21 portability law ?
As all forums and bulletins suggest it is received date.
Also note there is no limit to the number of job changes permitted under AC21. There is also no actual notification required, but we recommend notification. However, the job offer underlying a green card case must be permanent/indefinite. If a person is moving from job to job, it may appear that they do not have stable, permanent employment.
Generally, one can try to minimize the possible harmful impact of an I485 being denied by maintaining H1B status if one accepts new employment while the I485 is pending instead of using an EAD card.
It appears that it is always better to maintain the H-1B throughout the green card process as a redundant system especially as there are no regulations that explain AC21. It is better but does not appear to be required. Based on guidance it appears that AC21 portability requirements are met when the I-140 is approved, the I-485 has been pending for over 180 days and the new job is in the same or similar job classification as the original position sponsored.