Ok, so when we calculate shareholder's basis, we calculate stock and debt basis and the form 7203 that we are required to file with 1040 only has stock and debt basis limitation computations. I have never computed the ATM basis, and I am reviewing prior year returns by another CPA and ATM  "1986 Post depreciation adjustment" amount does not reflect anywhere in the stock or debt basis computation. So what is the purpose of the ATM stock basis computation, and when or why would this be needed? 

I want to make sure that I am not missing anything in calculating stock and debt basis for the purpose of how much of the loss is allowed by the shareholder or if the distribution is in excess of stock basis, if ATM items impact this. So this has no impact on this since it has no impact on the stock and debt basis. Correct? Am I overthinking? 🙂