REQUIREMENTS:

• Minimum amount of health insurance cover is US$100,000 or Baht 3 million - the rule states it must cover Covid.
• A health insurance policy from one of the Thai companies listed by the Thailand General Insurance Association (TGIA) will be acceptable. In the case of foreign health insurance cover, it will require a letter/certification from your Embassy OR apparently a notarized document signed by an authorized person that is then certified by the Ministry of Foreign Affairs (MoFA).(*) 
• If a person provides evidence of a denial of coverage by an insurance provider, they can qualify for the extension if they have at least 3 million baht on deposit in a Thai bank for at least 2 months before applying and (1) evidence of denial of coverage certified by the person's Embassy or by a notarized document from the health insurance provider certified by the MoFA. (*)   . At present, what type of document and how it is notarized that will be accepted by the MoFA for certification is unknown.
• Apparently one can use a combination method of health insurance and money in a Thai bank to be equal to or more than 3 million baht supported by the documents mentioned above. (*)
  

CLICK ON THE BUTTONS BELOW FOR AN ENGLISH TRANSLATION OF THE THAI IMMIGRATION POLICE AMENDMENT ORDER OR TGIA WEB PAGE

ExtractPoliceOrder-OA-Visa

TGIA Web Page for Health Insurance