How do I report an early retirement withdrawal tax? When I select it in Other Tax Situations, it says it doesn't apply to me, even though I filed a 1099-R.

The additional tax on early retirement withdrawals is normally calculated and applied automatically by TurboTax when you enter the Form 1099-R.  Sometimes the distribution code shown in box 7 of your Form 1099-R will indicate that an exception to the additional tax applies and the extra tax will not be imposed.  

Go back through the Form 1099-R section and pay close attention to any messages you may see onscreen.  If you are supposed to pay the additional tax, you will see that message and you will also see possible exceptions to the additional tax.