Here are the instructions for entering an amount on your Form 8960:
1. Click Federal on the left-hand side
menu.
2. Click Other Tax Situations across the
top.
3. Scroll down to Other Tax Forms and
click Start or Revisit by
Miscellaneous Tax Forms.
4. Click Start
or Revisit by Additional Taxes and Repayments.
Click Continue twice till you get to the screen below. This, from Turbo Tax Help on the subject:
How do I calculate the adjustment if I need to?
If you need to calculate the capital loss adjustment, you will need to complete the Lines 5a-5d - Net Gains and Losses Worksheet in the 2013 Form 8960 instructions. This adjustment must then be made going forward even if you are not subject to NIIT in a particular year. After completing the Lines 5a-5d - Net Gains and Losses Worksheet for 2013, enter the amount from line 2h of the prior year worksheet here. Enter the amount as a negative in TurboTax.
