Do you need a re-entry permit when leaving Thailand with a DTV multiple entry visa after 6 months?

It's a 5 year multi entry visa. You can come and go as you like. What is the question? Maybe I'm not understanding...

Oddly enough the muay thai school im talking said i will need re-entry for DTV. Was about to ask this question too.

But don’t forget to do the 90 days report when you stay more than 90 days in Thailand with Dtv

No need for re entry permit as you get a multiple entry visa.

You have to bend over a few times before leaving that's all.

No, I have entered 4 times. Each time I received a new six month stamp. My first stamp had an end date in January but my current one goes to April.

Why ?? Given its a multiple entry visa there seems little logical reason to try to retain a permission of stay, when a new entry will give a fresh 180..

Re-entry permits are used to maintain a current permission of stay through to its end date, but when holding a ME visa you will always get more (the max 180) than by using a re-entry and having 180 minus however much you used.

It's a 5 year multiple entry visa, you can enter and exit and re-enter whenever you like up to 180 days on any entry. Each time you enter you are stamped in for 180 days, you can stay 180 days or leave in 2 hours, up to you. You can do this 1000 times in the next 5 years.