It depends on whether the stock was sold. Once it is sold, then the costs can be deducted. To do this in TurboTax,
- From the Wages & Income section, scroll down to Investment Income and select Show More
- Stocks, Mutual Funds, Bonds, Other (1099-B) and Start
- Follow through the rest of the interview to enter your details
For more details, see How is a capital gain or loss calculated?