The station broadcasts at 105.3 MHz from Seattle (with a transmitter on Cougar Mountain), and includes translators broadcasting on 92.1 MHz (K221BG) in Aberdeen, Washington; 103.5 MHz (K278BH) in Astoria, Oregon; and 103.9 MHz (K280FF) in Chehalis, Washington. It is owned and operated by Crista Ministries. The station's main transmitting antenna is located on Cougar Mountain and transmits at 54 kW, while studios are located in the Seattle suburb of Shoreline.
- KCMS (HD) is a simulcast of "Spirit 105.3" on HD 1.
- "Pure Music Radio" is on HD 2.
- KCIS is simulcast in HD on HD 3.
The station is ranked 21st in the Seattle-Tacoma Arbitron PPM ratings data for September 2011 with 2.5 percent of the market share.
Prior to 1984, KCMS was known as KBIQ; the original calls were KGFM. KBIQ was used from about 1970 to 1984. That callsign now belongs to a Contemporary Christian music station in Colorado Springs, Colorado. The prior usage of the KCMS callsign was for a non-religious station broadcasting at 103.1 MHz from Indio, California. In that context, the "CMS" was promoted as meaning "Classical Music Station."
In the late 1960s into the early 1970s, KBIQ was one of the most powerful FM stations on the west coast of the United States. The station transmitted with an effective radiated power of 240,000 watts from the tower site of KGDN-AM at King's Garden (now Crista) in north Seattle (19303 Fremont Ave North).
The station signal could be heard from Vancouver, BC to Vancouver, Washington. The stereo on hour logo music was edited from Mission Impossible — Operation Charm and had a 747 going from left to right channels. John Pricer was the station voiceover. "From Vancouver to Vancouver, this is the all northwest sound of stereo 105, KBIQ in Edmonds" was their top-of-the-hour ID, along with slight variants.
KBIQ stood for "known by its quality," and played easy listening music and sprinkled with some Christian instrumental music and short local newscasts. The station was automated using IGM equipment and home recorded 14" reels, but had live news announcers during most important day-parts. The station also supplied music to K-Happy, a Christian formatted FM station in Albany, Oregon.
Other Seattle stations doing easy or modified versions of the format included KLSN-FM (now KJAQ) (from the late 1960s to early 1970s), KIXI-FM (now KJR-FM), KBBX, then KEZX (now KVRQ) (mid 1960's to 1979), KEUT (now KMPS) (mid-1970s), and low powered station KBRD (now KHTP).
The current Christian radio format debuted in 1996, first branded as 105.3 FM KCMS, then in 2002 as Spirit 105.3. The station now calls themselves Spirit 105-3.
KCMS in its current CCM format had 3 jingle companies produce jingles for them. GMI Media in Seattle was the first, doing 3 jingle packages. In 2003, with the rebranding to Spirit 105-3, the station tapped Chris Harris of Nashville to produce a jingle package to be used on 30 CCM stations nationwide. This was a 1 time agreement.
The station's current jingles are produced by TM Studios of Dallas, which started in 2006, after the Chris Harris agreement expired and no updates to the package were produced.