This arrangement covered only the weekday working hours. At other times, the Bethesda Fire Department served NIH. Within two years, the NIHFD staff increased to nine people working shifts and providing 24-hour coverage. In 1955, the first fire chief was named.
Over the years, NIHFD expanded its operations and is now a multi-service modern fire department equivalent to its municipal counterparts in surrounding cities and counties. Organizationally, NIHFD is in the Division of Fire & Rescue Services within the Office of Research Services in NIH's Office of the Director.
During its early years, in addition to providing emergency response, NIHFD handled fire prevention services. As buildings became more complicated and emergency needs increased, fire prevention duties were separated and are now handled by the NIH Division of the Fire Marshal with a full staff of engineers and inspectors. Fire reporting has been modernized to an automatic electronic system, which reports to NIH's own 911 operations center under the NIH Division of Emergency Management.