I can tell you about a retirement visa. You must be 50 years old or older, have a Thai bank account, have 800,000 baht in the account for 90 days OR have a letter from your embassy stating you have an annual income of 800,000 baht (or combination to make the 800,000 baht) and a type "O" (90day) visa. You take all your documents to immigration, pay the fee and get a one year retirement visa which is renewable annually. You must report your address every 90 days and have a re entry visa to return if you leave Thailand.