Patterns vary by country and region. In the United States, the employment arrangement of emergency physician practices are either private (with a co-operative group of doctors staffing an emergency department under contract), institutional (physicians with an independent contractor relationship with the hospital), corporate (physicians with an independent contractor relationship with a third-party staffing company that services multiple emergency departments), or governmental (for example, when working within military services, public health services, veterans' benefit systems or other government agencies).