Per Curiam
II
It is a well-established maxim of administrative law that “[i]f the record before the agency does not support the agency action, [or] if the agency has not considered all relevant factors, … the proper course, except in rare circumstances, is to remand to the agency for additional investigation or explanation.” Florida Power & Light Co. v. Lorion, 470 U. S. 729, 744 (1985). A “reviewing court,” accordingly, “is not generally empowered to conduct a de novo inquiry into the matter being reviewed and to reach its own conclusions based on such an inquiry.” Ibid. For if the grounds propounded by the agency for its decision “are inadequate or improper, the court is powerless to affirm the administrative action by substituting what it considers to be a more adequate or proper basis.” Chenery, 332 U. S., at 196; see also Smith v. Berryhill, 587 U. S. ___, ___ (2019) (slip op., at 15) (“Fundamental principles of administrative law … teach that a federal court generally goes astray if it decides a question that has been delegated to an agency if that agency has not first had a chance to address the question”).
As both petitioner and the Solicitor General representing respondent agree, the Sixth Circuit should have followed the ordinary remand rule here. That court concluded the FDIC Board had made two legal errors in its opinion. The proper course for the Sixth Circuit after finding that the Board had erred was to remand the matter back to the FDIC for further consideration of petitioner’s case. “[T]he guiding principle, violated here, is that the function of the reviewing court ends when an error of law is laid bare.” FPC v. Idaho Power Co., 344 U. S. 17, 20 (1952); see also Gonzales v. Thomas, 547 U. S. 183, 187 (2006) (per curiam) (remanding to agency based on failure by Court of Appeals to “appl[y] the ordinary remand rule” (internal quotation marks omitted)); INS v. Orlando Ventura, 537 U. S. 12, 18 (2002) (per curiam).
The Sixth Circuit, for its part, believed that remand was
