My wife has H4 stamping from previous employer. Now I am with new employer. Any issues at port of entry?

My wife has H4 stamping from previous employer. Now I am with new employer. Any issues at port of entry?
Any one travelled like that and what questions asked.
Thanks in advance.

Visa (valid) is just a travel document needed to enter the US. Assuming her H4 extension of status was done after you switched to your current employer, she can show the valid visa stamp, her current H4 I797 approval ( after you switched the employer) and copy of primary’s current H1B I797 to CBP at port of entry. CBP will issue I94 to match the expiry of her current I797.

I was told H4 extension only can be done once they are in usa. Cannot she travel without her H4 from new employer petition? My H1B approved petition from new employer is not enough? She valid stamping from previous employer…

This is correct. So you did change your employer when your wife was in India?

H4 is not based on your employer, rather it is based on your H1B status.

Is her previous H4 I797 still valid? If yes, she can travel using her existing valid H4 visa and I797 however note that CBP will issue her I94 till the expiry of her I797.

Once in the US you will need to file her extension of status based on your new H1B I797.

If her previous H4 I797 has expired, she will need to go for stamping using a copy of your current H1B.