Prior to March 17, 1996, municipal ambulances were operated by NYC EMS under the New York City Health and Hospitals Corporation, a public benefit corporation, which dispatched both its own ambulances and hospital ambulances. On March 17, 1996, NYC EMS merged with the FDNY, forming the Bureau of EMS. Employees of the newly formed bureau were considered FDNY employees and became eligible for transfer to firefighter within the department. As a result of the merger, the FDNY Bureau of EMS became the largest fire department-based EMS system in the United States.