Diverse and duplicative superintendence of national banks’ engagement in the business of banking, we observed over a century ago, is precisely what the NBA was designed to pre- vent .… Recognizing the burdens and undue dupli- cation state controls could produce, Congress included in the NBA an express command: “No national bank shall be subject to any visitorial powers except as authorized by Federal law ….” “Visitation,” we have explained “is the act of a superior or superintending officer, who vis- its a corporation to examine into its manner of conducting business, and enforce an observance of its laws and regulations.” [Citing in part 12 C.F.R. § 7.4000, the OCC regulation at issue in this case.]
Historical sources do not offer pellucid guidance on the contours of “visitation” in 1864, but they do confirm that the Act’s exclusion of States from any visitorial role not specifically authorized by federal law precludes the sort of state-law compliance investi- gation and enforcement that petitioner sought to un- dertake in this case.
While OCC has a variety of formal en- forcement mechanisms and punitive measures at its disposal, it encourages examiners to identify problems early, to discuss significant issues with a bank’s man- agement and board, and to provide guidance on how the bank may bring itself into compliance where it may be falling short.
Substantively, the regu- lation carries out a paradigmatic agency function by reasonably filling “gaps … as to the scope and definition of statutory terms.” Long Island Care at Home, Ltd. v. Coke, 127 S. Ct. 2339, 2346 (2007); see also, e.g., Smiley, 517 U.S. at 740-741 (ambiguities are to be “resolved, first and foremost, by the agency” implementing a stat- ute); NationsBank of N.C., N.A.
Here, there is no basis for concluding that Congress created OCC, charged it with exercising exclusive “visitorial powers” over national banks, 12 U.S.C. § 484, and gave it authority “to pre- scribe rules and regulations to carry out the responsi- bilities of the office,” id. § 93a, but withheld from that regulatory delegation the usual power to adopt reason- able implementations of statutory terms.