I thought to leave the country without renewing my extension. Can I start over by a visa exempt and apply for a new retirement in Chiang Mai ? 

Yes.

Apply for a Non Imm O Visa and then a 12 month extension.

Providing you qualify financially.

OP, no problem.

I assume your money has been in bank for some time (previous extensions).

In that instance no need to demonstrate funds came from overseas for your non O retirement application.

 

14 hours ago, Lite Beer said:

Apply for a Non Imm O Visa and then a 12 month extension.

My concern is if I can get 3 months non O in Chiang Mai. Or do I have to do it in Chaeng Wattana ?

4 minutes ago, The Theory said:

My concern is if I can get 3 months non O in Chiang Mai. Or do I have to do it in Chaeng Wattana ?

It can be done at the Chiang Mai immigration office.

Many years ago it could only be done in Bangkok.

5 minutes ago, The Theory said:

My concern is if I can get 3 months non O in Chiang Mai. Or do I have to do it in Chaeng Wattana ?

Chiangmai will issue.

2 minutes ago, ubonjoe said:

It can be done at the Chiang Mai immigration office.

Many years ago it could only be done in Bangkok.

Thanks Joe 

9 minutes ago, The Theory said:

Thanks Joe 

Always good plan to obtain your non O at same imm office that you will be obtaining your extension.

In your case CM

2 minutes ago, DrJack54 said:

Always good plan to obtain your non O at same imm office that you will be obtaining your extension.

Since they made the non-o visa available nationwide you have to apply for the extension at the same office where the visa was issued.

Are you currently  on an O-A visa?  
As others have mentioned you can apply for a Non-imm O after returning visa exempt.  I’ve seen reports here that Chiang Mai in particular requires those who recently abandoned their O-A visa extension to continue with the insurance required for O-A irregardless of them issuing a subsequent Non-imm O.

 

you might want to explore this further….  If this applies to you.  Sorry I don’t haven’t more specifics.  Perhaps other will chime in.

 

best wishes!

14 minutes ago, Tracyb said:

As others have mentioned you can apply for a Non-imm O after returning visa exempt.  I’ve seen reports here that Chiang Mai in particular requires those who recently abandoned their O-A visa extension to continue with the insurance required for O-A irregardless of them issuing a subsequent Non-imm O.

I have seen no reports of any office doing that.

There is no basis for an office doing that since the insurance is only required if a person has entered the country using a OA visa according the the immigration order for extension of stay.

20 minutes ago, Tracyb said:

I’ve seen reports here that Chiang Mai in particular requires those who recently abandoned their O-A visa extension to continue with the insurance required for O-A irregardless of them issuing a subsequent Non-imm O.

Where is one report? 

I returned to Chiang Mai on 30/12 with a visa exemption and started the process for a 90-day Non O six days later. Will get that on the 27th. And then ultimately get a one year extension in April. It's doable in Chiang Mai....provided you meet all of the requirements as mentioned by others. Need to start the process quickly after you arrive in-country if you want to avoid applying for a 30-day extension of your visa exemption and save 1,900 baht.