When legal scholars specializing in financial regulation have examined the Financial Stability Oversight Council (FSOC), their lens has usually focused on matters outside of the core public law expertise they are best positioned to contribute. This curious state of affairs is the consequence of the historical mutual disinterest between administrative law scholars and financial regulatory scholars. This Article helps bridge this divide, conducting a comprehensive administrative law analysis of the FSOC 's Section 113 designation program, and using it as a case study of an emerging trend in U.S. public law: increased contestation concerning the legal legitimacy of financial supervisory programs that provide for extensive, open-ended discretion on the part of regulators.