If you sell inherited stocks or mutual funds, at least some of the proceeds can be taxable income.  You'll need to know the basis of these instruments to determine if they're taxable when sold.

Please see Inheritance in the TurboTax article Cost Basis: Tracking Your Tax Basis and the TurboTax Help article What is the cost basis of inherited stock? for more information.

[Edited 3|17|2020 3:15 pm]