@CghLzh - Can you share a little more information about what was sold and if you received a tax form such as a 1099-B or 1099-CONS form related to the sale?? Are you referring to Column F on the Form 8949?? The 8949 rolls into the Schedule D. You would use Column F if the 1099-B is incorrect, you are excluding or postponing a gain, have a disallowed loss or other situations. The most frequent item in Column F - Is code W, Wash Sale.
Entering that information into TurboTax, you will enter the sale and there should be a check box that says "I need to adjust my total cost basis", here you will enter the amount in Column F and click on the adjustment code.
