@ltsmd
"but no amount appears in box 4 of the 1099B."
And that's exactly correct. The broker didn't withhold the money and pay the taxes. The broker passed the money along to the employer, who paid the money, and included these taxes on your W-2.
"When I do this" ,[enter the 1099-B as it reads], "it significantly changes my amount owed"
I assume that "changes my amount owed" refers to a big increase in taxes. That's because you're reporting the wrong basis for the sale because the broker is only required to report the amount you paid out of pocket to get the stock, ($0), instead of the correct basis. The correct basis is (per share "fair market value" used by your employer to calculate the compensation created by the GROSS amount of share in the grant) x (# of shares sold.) You enter the 1099-B exactly as it reads then correct the basis using the mechanism provided by TurboTax to get your basis "correct." A typical same day sale typically creates a small loss due to selling commissions and fees.
