Tourist visa yes - I've had one where I was asked back in 2017. Now I think about it 18 months is short, could even be over two years now - was it mid 2016 or 2017 they started to ask for it? I don't remember. Visa exempt no idea - I haven't had one in years.
Again - general rule is that if you transact with Chiang Mai Immigration they want a TM30 on file. The dozens upon dozens of reports of people being fined didn't come from no where.
Not new - a TM30 has been required to be on file for ANY transaction (extension, 90-day report etc) with Chiang Mai Immigration for at least 18 months, possibly longer. Hence the 1,600 baht fines for those who don't have one filed (they get caught when they go to do something else).
Despite being able to look it up on a computer they have a particular thing about wanting the confirmation slip in the back of your passport as well. It's the first thing they look for.
As an American you don't get a visa on arrival but a visa exempt entry and it's 30 days. For someone who describes themselves as a "Best Selling Author" you clearly lack basic Google skills.
Rejections at Mae Sai - and as Todd notes they simply won't let you exit vs stranding you in Myanmar, are rare. Presuming you haven't done your two land border bounces in the year you should be fine.
There are more reports recently, however, of people having a hard time getting 30 day extensions at CM Immigration if they have a long term history in Thailand on visa or visa exempt entries with extensions.
Joseph Michael Pedro III and for the record - now here on Non Imm B (BOI) and work permit. I just want to know whether overstays are actually NOW considered in Penang applications.