If the matching shares received resulted in compensation reported on a W-2 to you, then the basis for the GROSS number of matching shares received, (before any hold back or sale of shares for taxes), is the same as the compensation figure. (It's "as if" your employer paid you a gross amount of wages/salary in cash and you then immediately used that cash to by shares.)
If the 1099-B is reporting the basis to the IRS and is not using the correct basis, ($0 here), then enter the 1099-B as it reads on the default 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.
