Brown gives details during a morning (10 a.m.) news conference in Los Angeles. Five of the seven firms being sued are in Los Angeles.
Brown says the labs systematically overcharged the state by as much as 400 percent for blood, urine and other tests. The state wants to recover at least $100 million worth of the excessive charges paid by the program, which provides health services to the poor.
The attorney general's office began an investigation in 2006 after an executive of a competing medical lab filed a private false-claims action under seal.