Yes. You enter it as a sale of stock. Enter zero as the sale amount and 12/31/2016 as the sale date.
In TurboTax, go to: Federal Taxes > Income & Expenses
Scroll down to Investment Income and Show More
Select Stocks, Mutual Funds, Bonds, Other
Answer No to the 1099-B/Brokerage Statement question
Choose the type of investment
Use "worthless" in the description, e.g. ABC Company worthless stock, zero proceeds, sold on 12/31/2016
