John Muir Health is a hospital network headquartered in Walnut Creek, California and serving Contra Costa County, California and surrounding communities (all considered suburbs of Oakland and San Francisco). It was formed in 1997 from the merger of John Muir Medical Center (based in Walnut Creek) and Mount Diablo Medical Center (based in neighboring Concord). John Muir Health also offers complete inpatient and outpatient behavioral health programs and services at its Behavioral Health Center, a fully accredited, 73-bed psychiatric hospital located in Concord.