Immigration Site

Is it possible to change employer after I-140 approval in EB1 (outstanding reseacher category) or not? Do you loose your green card if you change employer after you receive your green card?

After you get your greencard, you can eventually move to another employer. However, that is not the expected outcome for this category in the short term. Leaving right away will look suspicious and will come back to haunt you. Although you did not specify, it would appear that you are NOW working for the I-140 petitioner, right? Merely having an approved I-140 is insufficient as there is no "portability" for this category.

An offer of “permanent” employment from a prospective United States employer.
[A labor certification is not required for this classification.]

Permanent, in reference to a research position, means either tenured, tenure-track, or for a term of indefinite or
unlimited duration, and in which the employee will ordinarily have an expectation of continued employment unless
there is good cause for termination.

The offer of employment shall be in the form of a letter from:

A United States university or institution of higher learning offering the alien a tenured or
tenure-track teaching position in the aliens academic field;

A United States university or institution of higher learning offering the alien a permanent
research position in the aliens academic field; or

A department, division, or institute of a private employer offering the alien a permanent
research position in the aliens academic field. The department, division, or institute must
demonstrate that it employs at least three persons full-time in research positions, and that it has
achieved documented accomplishments in an academic field.

Thanks Bigjoe5,

I have not yet started the application process. I am working as a senior scientist at a startup company with ~25 scientists, and they are willing to support me. I have a PhD in chemistry with 9 publications (67 citations) and still confused whether to go for EB1a or EB1b. I dont want to be tied up with an employer, would like the flexibility to move if I have a better Option. I consulted a lawyer and he told me, if we file i140 and i485 forms concurrently in EB1-OR category, I would be able to change employer after i140 form is approved.
Please suggest what are my best options.

Thanks for your time.

To re-emphasize on bigJoe5s point, immediate (or close) change of job will look suspicious later on (i.e. naturalization). If jobs are similar in description, you will at least have more room to answer questions if they ever question the intent.