Do I need to transfer my retirement visa to my new USA passport before my 90-day check-in in November?

You just continue to travel with your old passport and your new passport

Ronnie Staff . . . Thai Immigration does not transfer any Thai visa from an old to a new passport.

A Thai visa is a .pdf document issued by a Thai embassy or consulate outside of Thailand. This visa document cannot get transferred.

*** Immigration does only transfer their own stamps

That would be the stamp of the “1-year extension of (the) stay permit”, and the stamp issued for a re-entry permit.

Only these stamps will get transferred from an old to a new passport.

*** here I am, again as usual, explaining the difference between a visa and a stay permit.

No you don't need to. Just at time of the retirement visa renewal, on top of the renewal application, then you need to fill out the transfer stamp form with document copies.

Immigration will transfer to your new port

Do it now

Thailand, never guess. Always do everything right away. I do my 90 day retirement renewal as far ahead as I can in case there are any problems. I did have a problem once and that saved me

Come to Thailand with both passport. After arrival go immigration office where You stay and ask Them to switch Your non-o to new passport. I did it that way and didn’t cost anything. Maybe good to go to Your Thai bank to show and update Your new passport there as well if You have Thai bank.

Firstly get a 50 page passport

In the future you could have had them add more pages to your expediting passport not make a new one unless it was about to expire

With a new passport your going to have to make your report in person anyway. May as well kill two birds with one stone, but you need to transfer the stamps first