I-140 Portability

[konquistador]

Hi All, I have a question on I-140 portability. Can you please help me ?

a) As soon as the I-140 from current employer is approved , can we keep the priority date if we switch to a new employer or do we have to wait 180 days after the I-140 approval.?

b) Also, can we get extended beyond the 6 years of H1B visa in the new employment based on I-140 approval of the old employer (provided it is not withdrawn).?

Appreciate your help

Thanks,

Kon