People spend hours scanning the internet, participate in discussion forums, talk to lawyers and experts looking for information on changing jobs after 180 days of filing i 485. Based on my experience and general happenings, I decided I will write this blog so that it benefits everyone. AC21 is a law passed by President Clinton in 2000 - but the law never actually made it to the federal register and is followed by USCIS adjudicators through memos that are updated from time to time. So the law as such is non binding - which means there is no harm in not following the law, though it can be challenged in court (I am not sure how).

So what does this mean?
It basically means that one has to be ready to face some challenges if they change their job under AC21 law. But, the good news is, there is no recorded case of anyone who had to go back to their home country after their 485 is denied because they changed jobs under the AC21 law.

Lets do some more detailed analysis on this - lets discuss the scenario where you have already applied for i 485 and your 140 is approved and you have crossed 180 days after the 485 received date.
In this situation - you can change job but the new job has to be same or similar - there are a lot of resources on the internet, discussion forums and it does not hurt if you have to pay a small consultation fee to a immigration lawyer to understand if your new job is compatible.

So what is the issue?
Well, i 140 is a petition that is filed by your employer stating that they really need you for the job in future. Once you leave the employer - the employer is not obligated to keep that position and usually in most companies the HR department follow rules appropriately and send a notification to USCIS stating that the beneficiary for the immigrant visa petition has left the company and they don't intend to keep that position open. The employers do this for various reasons - small employers do not want to submit to USCIS the list of immigrant beneficiaries who are not working for them because they do not want to show proof that they have ability to support the immigrant petition. Big companies like to keep their immigration paperwork clean and do not like to misrepresent anything to USCIS.

What happens when an employer requests i 140 petition to be revoked?

First - lets discuss what happens if such a request never comes from an employer.
If you have changed jobs using AC21 and your 485 is being processed - the officer may not know that you have invoked AC21 and may just approve your 485. If you noticed USCIS that you changed jobs under the AC21 law - your letter may/may not reach your file in time or in place - there are various reasons - AC21 law being non binding - is available through memos to adjudicating officers and most times there is no formal process associated with handing AC21 paperwork - which means - it gets handled in various different ways.
In case the AC21 letter reaches your file - the Adjudicator can choose to review it and adjudicate your case or may decide to send a RFE requesting updated information about new job or may request an interview.

In case employer requests revoke of i 140
Their letter is formally processed. It is assigned to an officer. The officer usually has powers to use judgment in such cases and that's where AC21 beneficiaries get into issues.

So lets discuss what happens in this scenario.
USCIS through its memos, recommends that we send letter to USCIS about the new job change. Now, as there is no formal process, we are not sure if the letter reached our file. When the VO is processing the 140 revoke letter - sends acknowledgement that USCIS has received their request and their request has been approved and then looks into your 485. Technically - they are supposed to see if there is an updated letter on AC21 job change and continue with processing or request further information about new job and if they don't see any updated letter - they are supposed to send a NOID (Notice of Intent to Deny) on your 485 requesting you for an updated employment letter and give 30 days time to respond before denying your petition. Once the information is received, your 485 is back to normal and things continue to be normal.
In reality - some officers are sending denial notices on i 485 when the ex employer requests for revoking 140 and in some cases the denial notice goes to ex employer's lawyer or the beneficiary does not receive the letter in time.
What do we do when we get a denial on 485? Don't panic. Do the following steps
(1) If possible switch to a new job on H1b as against using EAD, though it does not hurt if you use an EAD to move - I will explain in detail.
(2) Always send your AC21 docs to USCIS using a good personal Attorney and track delivery and keep the proof
(3) Call USCIS and verify your address on their file
(4) Create your profile with USCIS and keep checking status from time to time
(5) If you get a denial on i 485 - talk to your lawyer and be ready to file for MTR (Motion to reopen) - you usually get 30 days to file for an MTR.

Now - lets look at what happens when you get a denial on 485 when you are on H1b or using EAD.
On a H1b visa, your status does not change and you can continue to work as long as your h1b petition is valid - but remember if you are on h1b extensions based on the approved 140 or labor - you may not be able to get further extensions if you do not file for MTR and get the 485 reopened. So the best bet is to be on h1b as you can carry on with your regular work and file for MTR. If you use EAD, EAD is associated with i 485 and when you get a denial on 485, technically your EADs will also cease. This is a grey area and people have interpreted this in different ways.

Now - the big question is - can I work?
Well different people have interpreted this in a different manner. Technically this is not your fault and denial can be reversed. So use your judgment after talking to a lawyer.

How will you deal with this?
Now - don't panic, follow these steps
(1) As soon as you get the 485 denial notice - talk to a lawyer - but don't inform your HR or employer immediately as they may not understand this situation and may not ant to deal with this situation.
(2) Ask your employer for a letter of employment and get it.
(3) File for MTR promptly.

Now - what happens when one files for MTR?
When you file for MTR you have to do nothing but just wait. It usually takes few weeks (5 to 7) for a decision and the worst recorded case as seen in a discussion forum is around 120 to 130 days. Once your MTR is processed you get back on track and everything is back to normal. If you are using EAD and got a denial on i 485 - you start accruing unlawful status. You must not exceed 180 days of unlawful status, so mark your calendar to make sure you don't cross that mark and leave the country by 179 days abandoning your MTR and GC process. Such a thing is rare because usually if MTR is taking longer time, you can appeal and request expedite (not sure how this can be done as I have not seen a case where MTR needed expedite). The most important thing in this situation is to keep your spirits high and also save enough money for MTR filing. When filing an MTR all evidence has to be submitted like, filing AC21 letter and record of delivery, proof of 180 days stay in company after filing 485 through pay stubs and email communication and other stuff that a lawyer will be able to guide you.

What happens if MTR fails?
Some suggest that we can appeal in court and win. I have no idea about this.

Finally -
The best part about all this is - AC21 has always worked though people go through hiccups.