"Received stock from a bypass trust when the second of my parents died. I understand that the stock bears the purchase date and cost as carried in the trust with no step-up."
That statement is somewhat ambiguous. When the first parent died the stock placed in that trust did receive a step up to FMV at date of death. When you actually received the stock at the death of the second parent, there would be no further step up.
Maybe that's what you really were saying, just wanted to be sure.
And the stock IS long term, as a matter of tax law. I haven't gone through the stock donation portion of TurboTax for a while but the BIG distinction for donation purposes IS "long term" vs. "short term". You're just as well of, and just as correct, to simply state you "purchased" the stock using the DoD of the first parent and the stock's FMV as of that date.
