In response to DavidD66
As you note, the entry to Form 8960, Line 5b can be entered manually via the Forms icon. Having done so, the Turbotax Error Check then asks to remove the manual entry, cautioning that the return might fail on e-file. My solution is to print the return and file manually. I need to do this anyway to explain the basis for the 5b entry. I did this successfully on an amended 2023 return. But I would prefer to do it electronically.
Your list of potential 5b entries omits "gain on sale of NUA shares, up to price at which shares were rolled over from a 401-k". NUA shares are employee shares in their company held in a 401-k pre-retirement and withdrawn at the time of 401-k rollover. Sales up to the rollover price are subject to capital gains tax, but not NIIT. The 8960 instructions for Line 5b treat this exception specifically. TurboTax should include a way of identifying this gain in their Q & A, perhaps in the calculation of capital gains (eg. "Are any shares sold NUA shares? What was the rollover price?"
