After reading the Tax Treaty between the US and Thailand, it specifically states that social security income and govt pensions can only be taxed by the US unless you become a resident AND a Thai national. A tax resident who lives in Thailand greater than 180 days is not a Thai National. See Article 20 and 21.

Please advise... I am over 50 years old and in the USA now and planning for a stay of up to a year in Thailand and I am a bit confused on what my visa plan should be. Should I do a 90 day STV or a NON O-A. Here's my question on the STV 90 day will I be able to renew and stay for a year without leaving the country or for the NON O-A will my social security income which will exceed 65,000 baht monthly eliminate the requirement for a 800,00 baht deposit in a Thai bank? Thanks for the help!