The historical development and contemporary nature of the American federal budget process have indicated that the process is fundamentally tied to politics. This paper discusses how and why this political dynamic exists in federal budget making. The study also attempts to learn whether or not differences in budget estimates produced by the Office of Management and Budget and Congressional Budget Office increase or decrease during times of unified or divided party control. Research findings indicate that the existence of divided party control is associated with higher differences in estimates. The study therefore suggests that politics may play a key role in budget estimations, and that this political dynamic ultimately adds to the politicization of the budget process.