This three-story building housed 144 male patients and contained the offices of Maybury's monthly magazine, The Fluoroscope. Radio programs originated here and were transmitted by earphones to patients throughout Maybury Sanatorium. The idea for this radio broadcast system began in 1932, and patients installed the wiring to each building so the hookup could carry auditorium programs, outdoor concerts, radio programs, and sanatorium announcements to every patient's room. In later years, as sanatorium operations were consolidated, the Annex was converted to the Children's Unit. The last young patients here were treated because of a 1966 tuberculosis outbreak at a nursery school.