What are the rules and requirements for extending a DTV visa in Thailand?

The 1st 90 days you report where you are living, the reason for leaving at 180 days is a separate report.

To extend a DTV inside Thailand you need to show you still meet the criteria. Easier to do a border run. Every entry gets you stamped in for 180 days

Just leave and come back. Go explore. Save yourself the headache.

1) 5 year validity is from date of issue NOT date first entered Thailand 2) You get stamped in for 180 days not 90 3) Extension for 180 days in Thailand you will need to show all your initial qualifying documents inc 500k plus depending on office certain residential papers

Your assumptions are incorrect. The length of time your $$ needs to be banked depends on what embassy you at thru. The 5 year period starts the day the visa is issued. When you enter, you'll get a stamp that is valid to stay for 180 days. You do not have to leave every 90 days... no idea where you came up with that little nugget of wisdom. You do need to file a 90 day report. It's multi entry, you can leave and come back getting another 180 stamp on entry. You can apply for one extension per entry by proving that you still qualify for the visa... basically you need to resubmit all the original documentation including treatment plans, course, proof of remote work, etc, as well as providing proof of finances. Wouldn't normally recommend an agent but in your case getting some assistance might not be a bad idea.