Have you checked your entries to make sure you did not mistype any? You seem to be the first to post about Turbotax making an addition error in the app. if you imported from say Quickbooks did every item come in?  

That was a great idea to switch to forms! The step-by-step method differs quite a bit from the forms method. Built into the forms (Other Deductions Worksheet) but not the step-by-step, in my case, are amortization, meals/entertainment, outside services/independent contractors, and other (line 35). The Other Deductions Worksheet form is missing interest. If I make all of these additions and subtract for interest, I do get TurboTax's result in the step-by-step method. It is very confusing that TurboTax does not ask these questions in the same section. The interest expense is found on form 1120S p1-2 line 13. All of my deductions do appear on form 1120S.

Depreciation did not come into play in this case as no depreciable assets were included in Other Deductions nor should there be.

After a little bit of detective work on my end, you have answered my question. Thank you.

See Critter-3's answer thread to look at the situation in forms method instead of the step-step-by-step method. TurboTax's Other Deuctions step-by-step method has some additional deduction entries and lacks several deduction entries that are in the forms method (Other Deductions Worksheet). Yet all of these are in the total for the step-by-step method! TuboTax should have kept these methods of entry consistent. It was very confusing.  

I did not import from any accounting software; I hand keyed all of my data. There were no typos.  

Thank you for your response.