The Thai immigration authorities have announced that from July, 2019 long stay visa holders over 50 years old ( retirement visas and extensions) will require medical insurance.
Coverage requirements are as follows:
This insurance has to be current at the time of visa application or extension renewal.
A policy issued by a Thai company would be the best bet as its validity can easily be confirmed. But they do say overseas issued policies will be acceptable but they are still working on the checking its validity problem.
This will no doubt affect a lot of foreigners budgets when renting a property. Landlords please note.