Hello Ron, I have already gone thru the material you have posted that AC21 is not mandatory and there is no need to proactively notify USCIS and still I have questions. After 185 days of filing I-485, I left my H-1b employer. I didn't have a job that time. Luckily within 2 weeks, I got the job and joined a new employer, after 1 month of leaving H1b employer. Meanwhile, H1b employer sent a letter to USCIS to revoke my H1b. That letter reached USCIS few days before I joined a new employer. I am not sure whether he had a note there that he doesn't support my I-140. I am getting a little anxious as what worst could happen. In this case, do you think, submitting AC21 documents to USCIS is worthwhile? Thank you.