Form 8960 calc not matching IRS calc

[kmbelford]

My federal income tax refund received is $11,732 shorter than anticipated as calculated by Turbo tax.  My IRS account indicates that they are calculating an addition Net Investment Income Tax (Form 8960) by this difference but don't show the inputs to determine how they calculated that.  I have pored over my return, following the numbers through TurboTax and reading the Form 8960 instructions and recalculating manually, and I don't come up with what the IRS is.  Has anyone else had this issue?

[Mike9241]

if this difference is entirely due to NIIT tax then then your line 16 and the IRS computation for line 16 for the 8960 differ by $308737 ($11732/.038). so you're probably looking for one big item that was excluded. you should receive a notification of the change including the details but you can call the IRS to inquire.

[kmbelford]

Thanks, @Mike9241 $308737 seems to be the issue but I think for some reason they are treating it as passive earnings whereas it is Sched C loss from an active business (not passive) as my 8960 form Part 1, 4a & 4b have offsetting values +/- of $308737.  But I don’t know why they would treat it as passive.

[BrittanyS]

If the IRS changed your return, you should receive a CP2000 notice that states what they changed and why.  If you feel it is incorrect, you can respond to the notice with the explanation and documents to prove your claim.  

@kmbelford 

[kmbelford]

Thanks, @BrittanyS .  I called the IRS this morning and they were confounded because my return indicates no mathematical error code and I didn’t get the letter as you indicated as I should have.  They did some additional research that indicated the difference on form 8959 but still no understanding on why.  I still firmly think the issue is with 8960.  They directed me to contact the Kansas City office so that is my next step.