Question about AC21

[wrizvi]

Would appreciate if anyone can answer this:

Does anyone know how to use AC21 if I want to go back to school for two years? Someone told me that its possible if the Employer doesn't cancel the 140 and gives a "Intent to Re-hire" letter.

 

[nj_skm]

This is not AC21 but a simple case of continuation of I-485 process.
The employment based GC is for future employment, under the understanding that once approved, the beneficiary will work full time for the sponsoring employer.
So you can go to school while the I-485 application is pending, as long as you intend to join the employer once the 485 gets approved.
Yes, if the employer doesn't cancel the I-140 and intends to hire the applicant after the 485 is approved, the petition is bona fide and the processing should continue by the USCIS.