This article describes the Environmental Assessment Instrument (EAI), a tool designed to help public health professionals analyze and then engage the environment in which programs operate. The prevailing environment is an important force that must be considered in an integrated systems approach when implementing programs and policies. The Division of Oral Health of the Centers for Disease Control and Prevention developed the EAI to facilitate the ability of a state oral health program to understand their environment and the impact it has on the achievement of performance objectives. EAI results are plotted on a four-quadrant grid that depicts four types of change-stagnant, disruptive, continuous, and sporadic. General strategies are suggested based on these categories of change. By assessing environmental influences, program and policy planners can determine salient leverage points within their environment, identify strategies to address barriers to success, and build on supportive features in the environment.