I am currently into my 1 year extension of my initial Non Imm "O" visa. During my first year I was required to make visa runs out of country every 90 days. This year I am able to just do the address reporting at the new Cheung Wattana office. I am planning on being in Aranyapratet around about the same time I am duew for my next reporting date. My initial visa had 4 entries and exits available to me. This year it appears they did not put any on the extention. My question is, am I able to exit the country and enter again? I was hoping to kill two birds with one stone since I am going to be near a border anyways.

You can come and go as many times as you want.

The 90 days starts again when you return. If you do not spend 90 days in the country you do not have to report.

BTW Your Non Imm Visa also had as may entries as you wanted but with a limit of 90 days on each entry.

A multiple entry Non-0 visa, valid for 12 months, actually has unrestricted number of entries giving 90 day permission to stay on each entry.

As you now appear to be on extension of stay you will need to obtain a re-entry permit from immigration if leaving the country to keep your permission to stay alive. Obtain from your local immigration office (where extension was issued). 1,000 baht single entry or 3,800 baht multiple entry.

I am currently into my 1 year extension

You must obtain a re-entry permit prior to any travel outside of Thailand or your extension of stay will end on exit.

As noted below, DO NOT FORGET TO GET THAT RE-ENTRY PERMIT, at the Immigration office where you got the extension. If you miss that little item, you'll have to start over with the extension process.

Mac