with OA you probably.need to be scared by.policy surprise, mandatory insurance introduced in nov 2019, after two years or more, inpatient cover need to raised from
*****
0 baht to 3 million! 7 fold increase! hope it won't go.up again after another 2 years
as far as i know, two kinds of retire.visa: OA (require health insurance to renew.visa, can only apply outside thailand) and O (insurance not required, can only apply after entry into thailand). You can google search for more info or even explore the thai.immigration website
i'd say mandatoryhealth insurance required by OA visa not quite useful as pre existing health problem are all excluded, so better opt for O retire visa which does not require this, besides it is not possible to change OA to O while in thailand, insurance premium will be very costly too as one gets older
i think the main poblem is that all pre existing health problem are excluded.from protection but you are most vulnerable because of these pre conditions