For a work permit, yes you have to change from the OA. You will have to work and pay taxes for 3 years to get citizenship. There is a Facebook group dedicated to getting citizenship. Hardly anyone does this but it is up to you.
I had an OA in Bangkok for 5 years as retired. If you are at the end of the first year of your OA then I believe that your first 1 year extension has to be the same as your original OA and that means you have to extend as retired for the first extension. The TM7 form for a 1 year extension has an entry at the bottom to enter the reason for the extension. This is where you enter "retired". I think for the second 1 year extension you can enter "marriage" on your OA visa. I also believe that even if you are on an OA visa, if you extend as married, you no longer need to have the required health insurance. Contact Tod Daniels about this.
If you don't want to go another year as retired then you will have to leave and re-enter to start the process for an O visa and subsequent 1 year extension.
Also, just because you got married it doesn't mean you have to extend as married. I continued to extend as retired after I married because the process and documentation is easier. You do have to meet the higher financial requirement for retirees though.
Pacific Cross. I chose a plan with a significant deductible. That keeps the price down. Medical care here in Thailand is both excellent and affordable. I am basically self insuring for routine medical care. The policy is there for a serious medical event such as a serious vehicle accident.
Because of my high(ish) deductible I haven’t tried to make a claim so I can’t say how well they pay claims. They have great customer service otherwise such as coordinating policies with your visa. I bought the policy when I was 62. In 7 years I’ve never had a medical bill over 20,000 baht. My deductible is 40,000 baht.
I was here on an OA for 6 years. For both the O and the OA you typically eventually end up getting 1 year extensions. While getting 1 year extensions the only difference between an O and OA is the required health insurance for the OA. There was no insurance requirement when I got my OA in 2017 so now I would recommend the O as a better choice. With an O visa you have more flexibility about insurance choices if you choose to have insurance.
Now I am on the 10 year pension LTR visa. That also has an insurance requirement though that particular requirement is a little more flexible. The LTR has some steep financial requirements. It is worth looking into as a possible option.
“As a holder of the "Wealthy Pensioner" category of LTR Visa, you are exempt from the Section 41 paragraph two foreign source income tax law, and therefore, you have no tax obligation in Thailand on any of the pension monies that you wire transfer from the US to Thailand. This exemption from the Section 41 paragraph two foreign source income tax law is provided to you under Royal Decree (No 743).
You also do not have to file any tax return in Thailand. For you to see this, see the attached PND95 Tax Return form. You'll see at the top of the form that only the "Highly Skilled Professionals" category of LTR Visa holders are required to file the PND95 tax return (not the "Wealthy Pensioner" category of LTR Visa holders).”