What are my options for extending my Non-O visa and obtaining a re-entry permit for multiple trips to Thailand?

this is a GENERAL LIST of requirements to get a year extension based on being over 50 (retirement) it is not office specific but it will get you in the ball park as far as what is likely to be required

That is why I said go to your office and get their hand out 🙂

It depends on your long term plans WRT staying in Thailand long term or just an occasional visitor. Be aware that any non O extension is 1 year and there are financial requirements so this would only make sense to get if you are planning a long term stay in Thailand.

When you arrive open a bank account as you’ll

Need 800k in the bank for two months before your extension

Why not go for the Non-OA while u r in USA. Then u would have multi entry and be stamped in for 1 year AND you could stretch it out to 2 years if you left and came back prior to the expiration of the visa validity.

Unless you want to apply for a 12 month extension when you return for your 2nd trip I wouldn't get a re-entry permit, get another 90 day Non-O while in the states. If you do want to apply for a 12 month extension make sure you put funds in a Thai bank on the 1st trip

Totally not uncommon at all to make you enter on a valid visa if you have one as the officer is under no obligation to let you enter free stamp, so your airport experience was typical and not unexpected.

What was the reason you thought you were going to get an extension on your 90 day single entry Non-O visa for? I ask because there is only a one year extension or a 60 day visit thai family extension (if you're married or have thai children) available.

You could buy a re-entry permit either at your immigration office or at the airport when you leave the country. Then when you come back in you would get stamped back in for the remainder of the original 90 days you got when you entered on the Non-O (remember a re-entry permit doesn't add any time to your stay just lets you exit/re-enter and keep that original entry stamp expiration date)

Then once you're back in the country you can apply for what ever extension you were thinking you could get. There is no requirement to have so many days left on your 90 day entry stamp to apply for an in country extension, you can do it right up to the day that 90 day stamp expires without any issues