The purpose of this handbook is to provide assistance to both new and experienced medical directors as they strive to provide the highest quality of out-of-hospital emergency medical care to their communities and foster excellence within their agencies. The handbook will provide the new medical director with a fundamental orientation to the roles that define the position of the medical director while providing the experienced medical director with a useful reference tool. The handbook will explore the nuances found in the EMS industry-a challenge to describe in generalities due to the tremendous amount of diversity among EMS agencies and systems across the Nation. The handbook does not intend to serve as an operational medical practice document, but seeks to identify and describe the critical elements associated with the position.