Thank you for trying to help, and I hear what you are saying, but I followed the directions on the IRS 8829 Instructions page (scroll down to Line 31 instructions and also see Part III instructions -- I am unable to post the link here for some reason). On my 2019 tax form that was prepared by my CPA, there was nothing entered at all on lines 32 and 33, so the value that resulted on line 44 was "0" for the depreciation that year. Following the same instructions this year for 2020 I added that "0" to the depreciation I took last year (2020) and got the value 1,947. That is also the value that results from multiplying the percentage they provided in the table on that IRS page (2.5641%), which appears on Line 41 by the Business Basis of the Building on Line 40 (75,914) on my 8829 form for 2020.
Line 31
Enter any amount from your 2020 Form 8829, line 44.
If you did not file a 2020 Form 8829, then your carryover of prior year excess casualty losses and depreciation is the amount of excess casualty losses and depreciation shown in Part IV of the last Form 8829, if any, that you filed to claim a deduction for business use of the home.
So, following the IRS instructions above, my "excess casualty losses and depreciation shown in Part IV of the last Form 8829" was "0" on Line 44 -- for 2020 and for 2019.
Line 42
If no additions and improvements were placed in service after you began using your home for business, multiply line 40 by the percentage on line 41. Enter the result on lines 42 and 30.
The IRS instructions above for Line 42 are the crux of the issue, I think. The number that the Turbo Tax system comes up with when it multiplies 75491 x 2.5641% = 1,975. But if you do that math, it is actually 1,947. This must be a calculation error in the system.
