Thank you! We will give this a try when we're on the ground in Hua Hin. Certainly more convenient than doing the DTV shuffle.
Our marriage certificate is currently being authenticated in DC now and then legalized by the Thai embassy also in DC, being handled by a courier service. Once it follows us to Thailand, we'll get it translated/legalized there too.
I'm no expert here but you would need a Florida courier service to get a certified copy of your marriage certificate, have it Authenticated for Thailand by the Florida officials (usually secretary of state), then do the part above (us state department and Thai embassy). Big pain in the... and expensive to fix when you aren't there now.
Sunida, I am now going through this process and it is exactly the steps you need.
I just want to add that the since the US (federal) State Department stamp in step #3 is in DC, you can (have to?) use the Thai Embassy in DC to certify that stamp, not your closest Thai consulate.
I am currently working with a service called Monument Visa (
) that offers a Thailand document legalization service. I went to my local county and got the certified copy of the license and then took it to my state's Secretary of State for the authentication stamp. Then I mailed it to Monument Visa who will walk it into the State Department (2-3 weeks instead of 6+) and then pick it up and walk it over to the Thai Embassy, then pick it up and mail it to me. Saves time and hassle, and worth the extra costs ($125 less fees, so actually pretty reasonable).
I commented to another reply, but we tried the DTV route, but the hospitals/doctors that I spoke to (including the one I consulted in November) all wanted to only set one appointment and then develop a treatment plan. We might end up having to do some combo of Retirement for my wife and tourist for me, then I get a treatment plan laid out and then I leave to apply for a DTV at a nearby consulate... but thank you for the warning, it looks like the medical treatment visa is a dead end for us.
So, reviewing the LA consulate's webpages on visas, the "Visiting non-Thai Family" page has a footnote: *Please note that the family of Non-O does not qualify for a Non-Immigrant Visa type O. They may instead apply for a Tourist visa or other types of visas they are qualified for.*. I think that means the dependent visa idea is a non-starter as well. If they offer this for the O-A they don't mention it anywhere in the webpage or in the evisa process. (sigh). Thanks for your feedback.