On August 27, 2020, the Tax Court issued its opinion in Van Bemmelen v. Commissioner(155 T.C. No. 4). The primary issue presented in Van Bemmelen v. Commissioner was whether the administrative record could be supplemented with evidence not considered by the IRS’s Whistleblower Office when it rejected the petitioner’s claim. Background to Van Bemmelen v. Commissioner In 2018, the petitioner submitted a Form 211 to the IRS’s Whistleblower Office (WBO). In this claim, the petitioner references