Thank you for the detailed response Tom! Last year I linked Fidelity account to TurboTax and it downloaded 1099-B automatically, populating all the numbers. If I understood you correctly, I have to include (report) my 1099-B with my tax return, regardless if the DDS (gain from sale) amount is already included in Box1 or not. However, I would need to correct something (the "wrong" bases?) because otherswise the gain form the sale will be reported twice: once in box1 and once in 1099-B. Did I get it right?
