There is something odd with 8960 in other ways. I had (non-passive) schedule C income which was reported by TurboTax on line 4a (correctly) and then canceled out by an equivalent negative value in line 4b, for a total of 0 on 4c (also correct, since non-passive Schedule C income is not subject to net investment tax). I recently got a BIGGER than expected refund from the IRS, so I checked the tax transcript. the IRS auto-corrected the return by REDUCING my income subject to the net investment tax by the amount that was supposed to just cancel out.
To make up some numbers: Suppose I had $10K in net interest income, line 4a income of $1K, and line 4b income of -$1K (for reasons described above). Line 8 should be $10K. But the IRS essentially made it $9K. How can this be? Am I missing something. I looked over past returns, and nothing like this has ever happened.
