What is the longest visa American citizens can obtain for Thailand and when does it start?

15 years Thai Privilege. 10 years on an LTR.

20 years if you get invited to apply

You have 90mdays to use it and the time starts from the day you enter.

Your age would be a good starting point

Nothing special about America—the same rules apply to all foreigners🙈🙈

How long do you want to stay in Thailand? If you're a tourist then the best or easiest option to stay a while is probably the METV which is a multiple entry tourist visa where you get stamped in for 60 days each time you enter, this is valid for 6months. You can stay almost 9 months with this visa if timed perfectly, add a few land border runs at the end and you could stay a year.

Otherwise there's the expensive options others have posted.

Elite visa 20 years.

20 years, elite visa. You need a lot of $$$ tho

There's nothing special about Americans visa-wise.

The longest realistic visa you can get if you're over 50 would probably be the OA visa which is one year.

The elite visa can be anywhere from 5-20 years.

LTR visa is 10 years.