First off, the visa is actually called a non-immigrant O-A visa.
To qualify you must be at least 50 years old, in good physical health and be financially able to support yourself while you are retired in Thailand.
The first thing you should do is contact the nearest Royal Thai Consulate and get the latest information from them. Rules and regulations change periodically and official web sites may not be up to date.
You will most likely be directed to a Thai Consulate or Thai Embassy web site to download the required forms. There is an application form, a medical clearance form, personal data form, and a police records check.
You will need a passport/visa size photo along with the application. The medical check will verify that you do not have tuberculosis, elephantiasis, drug addiction, third stage of syphilis, or leprosy. Allow a week or so to have the doctor run the necessary tests. I was only tested for tuberculosis and drugs.
The police record check is supposed to be an international check but most consulates will accept a local police check. Just go to your neighborhood police station and ask them to run a background check on you. You may have to wait one or two weeks for this depending on how busy your police are.
Once you have all of the above forms completed, you will need to show you have the necessary finances to support yourself. I supplied a copy of my latest pay statement, previous tax return, and a copy of my retirement account statement. I also drafted up a simple letter explaining how much money I currently had and an estimate of how much I would be receiving for my pension.
You will also need to provide a copy of your passport photo page.
I kept in contact with the Royal Thai Consulate in Hawaii and double checked to ensure I had everything that was required. The consulate near you may have different requirements for number of photos or number of document copies.
I dropped off my passport and paperwork on a Friday morning and my one year, multiple entry, non-immigrant O-A visa was ready the following Monday. Single entry visas are also available but multiple entry allows ease of travel. One thing to remember is that you must have at least 12 months remaining on your passport.
Once you retire in Thailand you will be required to check in with the local Thai Immigration office every 90 days and after one year apply for a one year extension. You will be required to have at least 800,000 baht in the bank or an equivalent pension or a combination of both. Ensure that the money in the bank is there for at least two months.
Acquiring the retirement visa is very straight forward and easy to do. Just ensure that you allow enough time prior to your departure.
You are now ready to enjoy your retirement in the Land of Smiles.