Ultimately you're going to report the adjusted cost basis when you report the sale. The "correct" way of doing this is to enter the 1099-B as it reads on the default TurboTax 1099-B entry form but then click on the "I'll enter additional info on my own " blue button. On the next page enter the correct basis in the "Corrected cost basis" box. The correct basis is (number of shares sold) x (correct per share basis, which includes the compensation per share)
TurboTax will report the sale on Form 8949 "as reported by the broker" but will put an adjustment figure into column (g) of the Form, a code "B" into column (f) of the Form, and the correct amount of gain or loss which includes the adjustment.
But as a practical matter simply entering the correct basis right in Box 1e would also work. If you report you taxable income correctly the IRS just doesn't have any leverage over you due to "style."
Tom Young
NOTE: TURBOTAX CHANGES THE SECURITY SALES INTERVIEW JUST ABOUT EVERY SINGLE YEAR. THE INSTRUCTIONS ON "HOW TO FIX" THE BASIS REFLECT THE STATE OF THE INTERVIEW FOR TAX YEARS 2016 AND 2017
