> How does USCIS monitor this 6 month period for GC processing?
Again, 2 different situations:
#1 If you want to change jobs under AC21 while the I485 is still pending (if you do AOS), there are two ways they check on whether you worked for the sponsoring employer: Either you file a letter with them indicating that you changed employers once you do it, or you have to file it in case they issue a 'request for evidence' on the I485 just before adjustment.
#2 If you get your GC through CP or if you didn't change jobs before getting your AOS approved, they don't really check whether you work for the employer.
The only times it comes up are: 1. you have a run-in with the law and they are looking for a reason to take your GC away 2. you apply for citizenship and have to give an accounting of what you did for the last 5 years. If at the citizenship stage they see that you jumped ship the day you got your GC, they can retroactively yank it (and with that your chance for citizenship). I don't think that this has been a major issue in a lot of citizenship proceedings, I just know that they do ask questions regarding your employment history if you got your GC employment based (just as they ask questions on your marriage if you got divorced right after entering the country on a marriage based GC).
> Is it temporary GC
In 'hadrons immigration reform act of 2006' (HIRA'06), employment based applicants would get a temporary GC for 3 years. After 3 years they have to file for 'removal of conditions' (just as marriage based applicants) At that point, they would have to proove that they where gainfully employed for 2 of the 3 years and that they made at minimum 95% of the 'proffered wage' on their LC while being employed. In my law, the nature of employment and the company would not be specified, just the fact that you have to make money and pay taxes. (But unfortunately I am just a little doctor and not a senior senator or cabinet secretary, so the chances of HIRA'06 getting passed are rather slim).
Simple answer: No, you don't get a conditional GC in employment based immigration although it would make a lot of sense.
> Does this mean you can not do anything else on the side during
> this 6 month period?
You can work on the side, just make sure that you can allways get an 'employment verification letter' from the sponsoring employer stating that you still have full time permanent employment with them and that the conditions of the labor certification still exist. Also, you have to have W2s from this employer in case they issue an RFE or investigate you in any way.
