By “pooling” legal and other resources allocated to different agencies, the executive creates joint structures capable of ends that no single agency could otherwise achieve. Pooling destabilizes core conceptions of administrative law. According to one influential account, for example, Congress exercises control over the bureaucracy through agency design. Pooling, however, calls into question the stickiness of those initial structural bargains. Through pooling, the executive reconfigures administration from within. If pooling renegotiates boundaries inside the administrative state, we might expect courts to actively police it. Yet judicial supervision, under current doctrines of administrative law, is quite spotty. Pooling can be a salutary response to administrative silos in our fast-changing and interconnected times. But pooling has a dark side. It can make administrative action less accountable and render legal safe- guards less resilient. The Article documents pooling across a range of policy domains, identifies its mechanisms, explores its structural and analytic implications, exposes legal questions that it raises, and pro- vides a preliminary normative assessment.