I'll differ with TomD8 here. You take a loss in a stock in the year it becomes "worthless." Simply being "in bankruptcy" or trading for pennies a share on the pink sheets doesn't cut it. And, of course, you typically don't get a 1099-B when a stock becomes worthless. You simply tell TurboTax that no 1099-B was received and it leads you through a somewhat different interview than the standard "1099-B" interview.
You might want to check with your broker to see if the stock really did become completely worthless in 2016. If it did, take the loss. You're now the proud owner of a completely worthless stock.
Tom Young
