Here are the facts from the California Department of Health Services:
Medical Marijuana Program
The Medical Marijuana Program (MMP) was established to provide a voluntary medical marijuana identification card issuance and registry program for qualified patients and their caregivers. The web-based registry system allows law enforcement and the public to verify the validity of qualified patient or caregiver's card as authorization to possess, grow, transport and/or use Medical Marijuana in California. To facilitate the verification of authorized cardholders, the verification database is available on the internet at www.calmmp.ca.gov.
In 2003, Senate Bill (SB) 420 (Chapter 875, Statutes of 2003) was passed as an extension and clarification of Proposition 215, the Compassionate Use Act of 1996. The Medical Marijuana Program, within CDPH, is administered through a patient's county of residence. Upon obtaining a recommendation from their physician for use of medicinal marijuana, patients and their primary caregivers may apply for and be issued, a Medical Marijuana Identification Card. Senate Bill 420 also required that the MMP be fully supported through the card application processing fees. Both the state and the counties have authority to cover their costs for the program through these application fees.