Can I extend my stay in Phuket beyond 90 days without returning to my home country?

Why not do it the right way?

Your post is a little contradictory, you say you are getting 60 day visa on arrival ( not possible on US passport as Stuart says, it’s 60 visa exempt) then you say you are coming on a tourist visa ? A basic tourist visa is 60 days or 2 months and not worth doing in advance now you get 60 days visa exempt on arrival plus 30 days extension. The only way to get 6 months without a visa is to leave and return a short time later. You can do as Stuart suggests using a border bounce company where you will spend a day in a bus with 6 or 7 other people, crossing into another country then returning after paying a modest fee to the company. You could also fly to Cambodia or Vietnam or Singapore for a day or two and return to be stamped in again for another 60 days plus 30 extension. There is a slight chance of being refused entry flying out and coming back but if you’ve never been to Thailand before it’s unlikely. In practice now there is no limit to the number of times per year you can enter Thailand but if the IO who is stamping you in thinks you are trying to live in Thailand without the correct visa they may issue a warning upon entry or deny entry. If doing the fly in fly out option it’s as well to have the three proofs with you. 1. 20k Thai baht in cash 2. Proof of accommodation in Thailand 3. Proof of onward travel out of Thailand within 60 days of entry. A lot of people will probably comment about never been asked for the 3 proofs , but as someone who has travelled into Thailand on average 6 times a year for the past 4 years I’ve been asked for onward travel and accommodation proof 3 times but never been asked to show the money.

Sorry about the long response.

You can only do one extension unless you’re married Thai or have a Thai child. Best option is to get a six months multiple entries tourist visa before you come in order to avoid going back to back on visa exemption.

You don’t get a “visa on arrival” with a US passport. With no visa you’d get a visa exempt entry stamp for 60 days. You can extend that once for a further 30 days.

To get longer then it would be advisable to use a “border bounce” company that facilitates such. They know the wheels to grease and will get you back in.