Retaining an EIN when merging an S-corp into a surviving C-corp. Looking for guidance!

Hi there!

I'm looking for assistance with the following questions:

1. It seems unclear to me whether merging a CA S-corp into a DE C-corp will allow for a retention of the CA corp's EIN. The DE corp is newly formed and has no EIN. More importantly, perhaps, is that the merger is more of a re-organization under the IRC that only is a change in name and place. Ownership and everything else remain unchanged.

2. I have the same question for merging a CA LLC into a DE LLC.

3. I have the same question for merging a CA SMLLC into a DE SMLLC.

4. Additionally, with respect to the corporations, can the surviving DE corporation in this example assume the S-corp status during the merger? If the EIN can in fact be maintained, would the S-corp classification go with it? Does the classification of the two corporations affect the ability to assign the CA corp's EIN to the surviving DE corp?

Thank you in advance! I would be happy to engage with someone with specific experience here.