Do I need to purchase O-A health insurance for the entire year before entering Thailand?

When applying for the O-A visa, it is recommended to purchase health insurance for the entire duration of your stay. The validity of your visa stamp will correspond to the length of your insurance. While you can acquire insurance later in Thailand, it complicates the process, as adjustments must be made at an airport immigration office rather than a regular immigration office. Therefore, obtaining a full year's insurance before arrival is advisable to avoid hassles.