If your 1099-B shows the cost basis, but did not report it to the IRS, you will enter your cost basis in and proceed as with any other transaction.
If the cost basis was not reported because your brokerage does not have it (i.e. the basis is blank) then you will need to provide the information from your records, or look it up online.
To do this in TurboTax,
- In your open Federal return, choose Wages &
Income
- Scroll down to Investment
Income and Show more
-
Start or Revisit Stocks,
Mutual Funds, Bonds, Other
-
Add a sale and answer Yes, you got a brokerage statement.
- On the next page "Choose your
bank or brokerage,"
scroll down and select "I'll type it in myself."
-
Enter your
brokerage name and Continue
- on the page "Tell us
about your Brokerage 1099-B" choose the radio
button that applies to your situation and that will open the transaction interview for you, (If you need
more info at any time, select Learn More.)