What happens to current passport and H1B visa after passport renewal in USA?

Hi Anil,
My Passport will expire towards end of Dec 2018 and H1 visa is valid till mid 2020.

I’m planning for a 2-weeks trip to India during Nov 2018. My question is If I renew my passport now, what will happen to my current passport and visa? Also, Do I need to schedule visa interview to get a visa stamp on my new passport. Else, Is it a good idea to apply for renewal after my trip (Roughly 1 month before expiration date). Thanks!

You can apply anytime you like. My advise would be to get it renewed from USA and then travel to India. It is easier and faster to renew here than in India.

Visa still Valid in old expired passport - Do we need to renew Visa too?

Your current H1B stamp will remain valid as long as it has the validity written on it.
Whenever you renew your passport, you have to carry all old passports as well with you.

Your visa stamp in old passport remains valid and you can use it to re-enter USA. There is no need to get a new visa stamp if the current one is valid at the time you re-enter USA.

Does that answer your question?

Yes. It does! Thank you for the quick response!