A student sit-in protest led to the creation of the station. On February 3, 1973, KBCS went on the air with 10 watts of power with used equipment donated by Dorothy Stimson Bullitt of KING-FM. It remained student-run until 1988 when Bellevue College administrators hired a general manager for the station and it adopted a community radio model. Over time the station became self-sustaining, funded primarily by listener donations.
A very wide variety of music, including EDM, Funk, Latin, Brazilian, Underground Hip Hop, Blues, Gospel, S. Asian Music, African Music, Reggae, Contemporary Classical, world, jazz and Americana, is heard on 91.3 KBCS, as well as local and national news and information. It is managed by a small staff, along with over 150 volunteer hosts, producers, journalists and administrators. The station offers training in broadcast production and journalism to the public. KBCS has launched the careers of a number of noted regional and national public radio professionals.