In the United States, government operations are split among three branches: legislative, executive, and judicial. There is no constitutional provision establishing administrative agencies. Agencies are created by one of the three branches of government—usually Congress. After creation, most administrative agencies fall under the aegis of the executive branch.

Some scholars have referred to administrative agencies as the fourth branch of government. Agencies do not actually constitute a constitutional fourth branch of government. The Constitution establishes only three branches and, as you will study in greater depth, agencies are accountable to these branches.