With a Disqualifying Disposition the compensation income is already reported on your W-2. Your issue is making sure you use the correct basis reporting the sale so you don't overstate your profit and report that income twice.
On a Disqualifying Disposition the discount on the day you bought the stock becomes the compensation reported on your W-2, so you want to make sure your add that discount to the basis reported on the 1099-B which is only going to report your "out of pocket" costs.
The very easiest way to do this is to simply report the sale of the stock on the default spreadsheet-like, "fill in the boxes", TurboTax 1099-B input form. Enter the 1099-B exactly as it reads. Tick the box next to "This sale involves an employee stock plan (including ESPP) or an uncommon situation." Click the blue "Start Now" button that shows up and then click the radio button next to "My 1099-B has info I know isn't right, or it has extra info I need to add." That will allow you to add the missing amount of basis and TurboTax will show all this correctly on Form 8949.
You can also enter the sale using the ESPP step by step interview. Again, enter the 1099-B exactly as it reads. Tick the box next to "This sale involves an employee stock plan (including ESPP) or an uncommon situation." Click the blue "Start Now" button that shows up and then click the radio button next to "I have sales from an Employee Stock Plan, including ESPP, NQSO, ISO, RS and RSU." Tick the ESPP option. However I recommend the first method since some people get confused by this interview.
Tom Young
EDIT: SINCE THE SOFTWARE WRITERS AT TURBOTAX SEEM TO CHANGE THE INTERVIEW CONCERNING THE SALE OF SECURITIES EVERY YEAR, THE DESCRIPTIONS ABOVE CONCERNING THE TURBOTAX PROGRAM ARE ONLY APPLICABLE TO THE TURBOTAX PROGRAM FOR THE YEAR THE QUESTION WAS ASKED.
