Get your taxes done using TurboTax

If the cost basis is $0 on your Form 1099-B it may mean that the broker does not know the correct cost basis. They may or may not report the $0 amount to the IRS, but in either case you can adjust that amount to report the correct cost basis.

You can enter the sales summary of each box code. You will start by entering the description of each section referencing short-term or long term and how that group of investments is reported to the IRS (short term bases reported, not reported, etc...) Your entry there will determine the code that TurboTax will assign automatically. 

On that same screen, you will enter the cost basis as reported in box 1e on your Form 1099-B. If the cost basis is wrong or missing, you will check the I need to adjust the cost basis box and you will see an option to enter an adjustment to the basis reported, and you can choose the code that best explains the reason for your adjustment.