Cost basis of partially inherited real estate

[Michael Alvarez]

My mom passed away a few years ago, and the main asset that she left behind was her house. I have three siblings, so each of us were entitled to 25% each. However, my two youngest siblings did not want to keep their interest in the house, so my older brother and I decided to buyout their shares.

My mom's estate went through probate. An appraisal was done to determine the FMV of the house. In the end, the house was distributed from the estate to me and my older brother with 50% ownership each. The buyout payments were also included in the distribution order.

The buyout payments do not exactly align with the appraisal, and I am having a hard time getting a clear answer on what my cost basis is. I have asked the probate/tax attorney, as well as paying for some time with a CPA, but they are giving differing opinions. One says that my basis is simply 50% of the appraised value, while the other says that only my original 25% share receives a step-up in basis and the other basis for the 25% that I acquired is determined by how much I spent.

Since the asset passed directly from the estate to me and my older brother, without another transaction in between, I am leaning towards just using the appraised value. Does anyone have any insight on this? Thank you in advance.