FIrst, with the TurboTax program, if you just arbitrarily change the ownership percentage, that will completely skew the depreciation, to include the depreciation history, current year depreciation, and future depreciation. So just changing the percentage is not the way to go, as it flat out will not work correctly with any version of the TurboTax program.
How you do it "correctly" depends on how the recipient received the deceased father's ownership share. For example, did they inherit it? Or did the mother inherit it and the mother gifted it to the son? It would be normal if the parents were married at the time of the father's passing for the mother to inherit it, unless specified otherwise in a last will and testament. It would also matter if the parent's live in a community property state, as that determines how the step-up in basis is figured.
