Single Judge Application; deficient reasons and bases; It is the Board’s responsibility as factfinder to assess and weigh the evidence.18 Here, we simply do not know the weight, if any, the Board gave this evidence in assigning a rating for appellant’s GERD. It is important for the Board to make such a finding in the first instance.19 We recognize that the Secretary offers several arguments about why extraschedular referral is not warranted for appellant’s GERD. However, it is ultimately not his prerogative to provide an explanation that the Board did not. As we have often said, the Secretary cannot make up for the Board’s deficient statement of reasons or bases.20; 19 See Tadlock v. McDonough, 5 F.4th 1327, 1337-38 (Fed. Cir. 2021) (“Where additional findings of fact are necessary regarding mattes open to debate, the proper action is for the Veterans Court is to remand to the Board for consideration of those facts in the first instance.”).; 20 See In re Lee, 277 F.3d 1338, 1345-46 (Fed. Cir. 2002) (“‘[C]ourts may not accept appellate counsel’s post hoc rationalization for agency action.’” (quoting Burlington Truck Lines, Inc. v. United States, 371 U.S. 156, 168 (1962))); McCray v. Wilkie, 31 Vet.App. 243, 258 (2019) (“[T]he Secretary’s impermissible post-hoc rationalization cannot make up for shortcomings in the Board’s assessment.”); Simmons v. Wilkie, 30 Vet.App. 267, 277 (2018) (holding that the “Court cannot accept the Secretary’s post-hoc rationalizations” to cure the Board’s reasons-or-bases errors), aff’d, 964 F.3d 1381 (Fed. Cir. 2020); Smith v. Nicholson, 19 Vet.App. 63, 73 (2015) (“[I]t is not the task of the Secretary to rewrite the Board’s decision through his pleadings filed in this Court.”).;