Scholars have largely ignored one of the most important ways in which presidents influence the administrative state in the modern era, that is, by creating administrative agencies through executive action. Because they can act unilaterally, presidents alter the kinds of administrative agencies that are created and the control they wield over the federal bureaucracy. We analyze the 425 agencies established between 1946 and 1995 and find that agencies created by administrative action are significantly less insulated from presidential control than are agencies created through legislation. We also find that the ease of congressional legislative action is a significant predictor of the number of agencies created by executive action. We conclude that the very institutional factors that make it harder for Congress to legislate provide presidents new opportunities to create administrative agencies on their own, and to design them in ways that maximize executive control.