I sold all of my units in Energy Transfer in 2020 in one sale. I bought the units in 2010 and over the years have accumulated an adjusted cost basis that is considerably negative. The broker's Form 1099B shows the original unadjusted basis. The 2020 Sales Worksheet from Energy Transfer says to include their negative average cost basis on Form 8949 Column E but Turbo Tax will only allow me to plug in a number of $0 or greater for the adjusted basis on the worksheet. Is there a workaround here that would allow me to plug in the correct negative number? I'm also plugging in the gain subject to recapture on Form 4797 Part II line 10 and a loss adjustment on Form 6251 line 2K for AMT. The instructions say to also include the gain subject to recapture as a negative number on column G of Form 8949 to get to the correct basis.
