Hi everyone. I had been living here on extensions due to marriage for the last few years, but lately I have had to return to the States for a few months every year. I came on an one year non-0 this time, and my 90 day is coming up. I will be returning to the States in less than two months. As I understand it, I can get a 60 extension and avoid a border run. If that is still the case, want do I need to bring with me to immigration.

You can apply for a 60 day extension to visit your wife.

Your wife will need to be with you when you apply.

You will need your marriage certificate, copies of your wife's house book registry and ID card,

You will need proof of residence unless living where your wife's house if is for.

Thanks Ubonjoe-- I read about that earlier in this post but it was dated 2015. I just needed to be sure that was still the case. What is the fee?

Since I am thinking about it, I do have another question. I came into the country on Dec 1 with a one year multi Non-o. I will go back to the States at the end of April and return to Thailand at the end of Oct or no later than late Nov. I would be returning before the original one year is up. I will more or less be doing the same as this year, leaving again at the end of April. What would be my best option. I didn't know I could get an extension on the 90 day before. That is why I got the one year, knowing I would be here for 5 months. If I came back before the one year is up, would I get another 90 day that I could get an extension on, or would I need to get a 90 day visa beforehand?

you will get a 90 day entry on all entries made before the expiry date of the visa, and you can get a 60 day visit Thai wife extension once only on each entry. 

on the extension theme have you or more correctly the owner of the property where you stay, completed a form Tm30 at your local immigration office

About the tm30, not this time around. My wife would be going with me to immigration.

depends on the office but you may be required to complete one, and your wife may be fined, just a warning.

Thanks for your help. Got the 60 day, they didn't ask about the tm-30, Korat office