California Department of Insurance (CDI)
Information/questions: (800) 927-4357

Sacramento Office
300 Capitol Mall, Suite 1700
Sacramento, CA  95814

San Francisco Office
45 Fremont Street, 23rd Floor
San Francisco, CA 94105

Los Angeles Office
300 South Spring Street, South Tower
Los Angeles, CA 90013

Has an online portal for filing complaints and a wealth of information on many kinds of insurance, from health, auto and homeowners’ insurance to pet insurance and workers’ compensation.