Assuming you will not be breaching a contract with your current employer if you decide to change employers, the answer depends upon your profession:

1. If you are a Registered Nurse or Physical Therapist: because you are not subject to labor certification, the INS has a procedure in place to allow a change in petitioner. Essentially, the INS instructs you to appear at your adjustment interview with a new I-140 and support package from your new employer; the adjudicating officer is supposed to approve the petition and that's it. We've actually done this a number of times over the years, but often there are real problems:
   
   
   1. the adjustment officer is unaware of his authority to approve the new I-140;
   2. the former employer revokes the underlying approval upon learning of your departure and you lose your priority date!
   We've seen both happen...the best advice is to sit tight if possible. If your job is in jeopardy or things are so miserable that you are willing to risk the foregoing, you can switch.
   
   
2. ALL OTHER PROFESSIONS (including OT's, SLP's, Programmers, and everyone who's not an RN or PT): Please see our article which covers this and other areas under the new American Competitiveness in the 21st Century Act (AC21) legislation.