On November 30, 2021, the Tax Court issued a Memorandum Opinion in the case of Plateau Holdings LLC v. Commissioner (T.C. Memo. 2021-133). The primary issue presented in Plateau Holdings LLC was whether the 20% accuracy-related penalty applied to the portion of the underpayment not attributable to a valuation misstatement, that is, to the portion of the underpayment resulting from the Tax Court’s conclusion that the petitioner was not entitled to a charitable contribution deduction