In the HSA section, indicate that you received money from the HSA, then enter the Form 1099-SA that you'll receive near the end of January and indicate that none of it was used for medical expenses. TurboTax will then include the distribution in income and, if you were under age 65 at the time of the distribution, will include the 20% additional tax. These are calculated on lines 16 and 17b of Form 8889, respectively.