Opinion of the Court
trustworthy, and thinks she has good reason to keep her data private, her rejection of an applicant’s demand need not make a difference. So too when a court reviews the ALJ’s decision under the deferential substantial-evidence standard. In some cases, the refusal to disclose data, considered along with other shortcomings, will prevent a court from finding that “a reasonable mind” could accept the expert’s testimony. Consolidated Edison, 305 U. S., at 229. But in other cases, that refusal will have no such consequence. Even taking it into account, the expert’s opinion will qualify as “more than a mere scintilla” of evidence supporting the ALJ’s conclusion. Which is to say it will count, contra Biestek, as substantial.
And much the same is true of Biestek’s claim that an expert’s refusal precludes meaningful cross-examination. We agree with Biestek that an ALJ and reviewing court may properly consider obstacles to such questioning when deciding how much to credit an expert’s opinion. See Perales, 402 U. S., at 402–406. But Biestek goes too far in suggesting that the refusal to provide supporting data always interferes with effective cross-examination, or that the absence of such testing always requires treating an opinion as unreliable. Even without specific data, an applicant may probe the strength of testimony by asking an expert about (for example) her sources and methods—where she got the information at issue and how she analyzed it and derived her conclusions. See, e. g., Chavez v. Berryhill, 895 F. 3d 962, 969–970 (CA7 2018). And even without significant testing, a factfinder may conclude that testimony has sufficient indicia of reliability to support a conclusion about whether an applicant could find work. Indeed, Biestek effectively concedes both those points in cases where supporting data is missing, so long as an expert has not refused an applicant’s demand. See supra, at 7. But once that much is acknowledged, Biestek’s argument cannot hold. For with or without an express