What should I know about the NON-OA visa and its renewals in Thailand?

A Non-OA Visa is multi entry so if you have insurance you will always be stamped in for 12 months up to the expiry date unless your insurance is less than 12 months. You can get 2 years in Thailand from a Non-OA with good planning but when the Non-OA expires you will need to buy a re-entry permit or lose your second year.

Don't think you understand how a non-OA visa works. The reason you were initially stamped in until July is clearly written on your visa. It's because that's when your insurance ended. A requirement of the non-OA visa is to have the required insurance.

Every time you enter Thailand until 26 July 2024 (the expiration date of your visa) you'll be given a new 1 year stamp (or until the end of your insurance, if less than 1 year).

This means if you buy a new insurance policy and leave Thailand and re-enter on July 26th, you'll get a new 1 year stamp until July 2025.

This is not an extension of your visa. This is how a multiple entry visa works. You get a new stamp every time you enter while the visa is valid. That's why it's called multiple entry.

You shouldn't try to extend this stamp. Because you got the non-OA visa instead of the non-O visa, you are required to have the $100,000 insurance forever. That means when you go to extend you'll be required to show both 800,000 in a Thai bank account AND the $100,000 insurance.

You should go back to the US and get a new non-OA visa so you don't have to keep 800,000 in a Thai bank account.

If you have no issues keeping 800,000 in a Thai bank account then you should leave Thailand after your visa expires (after 26 July) without a re-entry permit, though I'd wait until May 2025 if I was you, and then return without a visa and enter on a 30 day visa exempt stamp. Then you can apply for a 90 non-O visa at your immigration office and only be required to show the 800,000 and not have any insurance requirement.

IMPORTANT: If you leave Thailand after your visa expires (26 July) you MUST purchase a re-entry permit if you want to keep your entry stamp alive. Otherwise it will be void as soon as you leave and you'll only get a 30 day visa exempt stamp when your return without a visa.