Of late, the substance and implementation context of federal regulatory policy have been altered. With the development of new social regulation, it is not uncommon for federal agencies to be legally charged with holding other federal agencies accountable to the law. The focus of this study is the Environmental Protection Agency's regulatory experience with the Tennessee Valley Authority as the former sought to apply provisions of the Clean Air Act of 1970 to the operations of the latter. The purpose of the study is twofold. First, it seeks to describe what can happen when one federal agency tries to regulate another. Second, it attempts to assess tentatively the efficacy and implications of intragovernmental regulation. The EPA/TVA experience suggests that federal agencies can be made distinctly vulnerable to public regulation; that as a form of bureaucratic oversight such regulation is a promising supplement to traditional overhead democracy techniques; and that challenges raised by public agencies to implementation may not be as inappropriate, insurmountable, or dysfunctional as commonly assumed.