The federal Fifth Circuit’s opinion vacating a Securities and Exchange Commission administrative law judge’s decision in a securities fraud case is the first time since 1935 that the court used Article I’s nondelegation doctrine to invalidate congressional delegation to an agency and could drastically affect the use of in-house administrative judges. While the court did not directly attack agencies’ ability to legislate, the opinion’s broad sweeping language about separation of powers and accountability suggests that agency rulemaking authority could be ripe for challenge. Cases involving securities fraud, Medicare, disability benefits, immigration and more could sit on dockets for years waiting to be adjudicated. This article is the first in a series examining the federal appellate court’s decision in Jarkesy.