My parents had an irrevocable trust that closed when they died in 2020.

[CindyS]

I was one of the beneficiaries. I sold some of the stock. When determining the basis, what date do I use--the Trust's date or the date the stock was transferred to me?

[M-MTax]

Didn't you get a K-1? Didn't someone file a 1041 for the trust? If the trustee gave you shares of stock which you sold your basis would be valued as of the date of death and that's the date you acquired the stock.....long term no matter what. Only thing is if this trust was not a grantor type before they died. Ask the trustee.