For me it looks like the IRS on line 8 of Form 8960 added line 4b instead of line 4c. Since I had a lot of self-employment income, this makes line 4b and therefore line 8 highly negative. Because NIIT is calculated on the smaller of line 8 and another amount, this incorrectly wiped out my NIIT. I know they are underfunded and understaffed, but how in the world is the IRS still making a mistake like this in March??? This is not exactly a rare scenario.
