回複：看我急得是140已批，我不是NIW。

Just my 2cents. Please also consult other people.

I think the key is when you left your previous company. If you left your previous company after 180 days since your I-485 was pending, you can use AC21 and only need to ask your current company to write a letter to USCIS stating that the position you have now is similiar to the position you had in the previous company and they would like to hire you permenantly. If you left your previous company before 180 days since your I-485 was pending, theorily, your previous I-485 application is not useful any more. You need to redo PERM/I140/I485 in the current company. But you can use the priority date of the approved I140 in the previous company to submit your current I485.