This is an area that has a number of unaddressed questions and letters have been sent to Treasury requesting clarification on exactly how to address the expenses and the timing of recording the tax-exempt income.
The issues are around whether some of these items are recorded through AAA or OA and when is it recorded.
Since this is not clear, and I'm assuming that you have extended your S corp return, I would not rush to prepare your 1120-S. I would wait until there is further guidance. Doing anything else, and you will run the risk of potentially having to amend the 1120-S and also your personal tax return.
Unfortunately, I cannot give you any time frame. These things move slowly.
*A reminder that posts in a forum such as this do not constitute tax advice.
Also keep in mind the date of replies, as tax law changes.
