The California Area Indian Health Service provides the healthcare delivery system to the State of California, the home of the largest population of American Indians/Alaska Natives (AI/AN) in the country. According to the 2000 Census, California's Indian population was 333,346 in 2000. The 2000 Census also indicated that there were 294,216 additional people who stated that they were American Indian and a combination of one or more other races. California is home to 107 federally recognized tribes.

There are presently 31 California tribal health programs operating 57 ambulatory clinics under the authority of the Indian Self Determination Act. IHS funds eight urban health programs that operate under the authority of the Indian Health Care Improvement Act. In FY 2001, California tribal health programs had 119,362 registered users and 69,238 active users. Registered users are a cumulative total for all Indian patients ever seen at tribal facilities, and active users are those that have accessed care during the past three years.

None of the tribal facilities and programs currently operating in California originated as facilities previously operated by the IHS, as is the case in other IHS areas. Population sizes and dispersion of tribal groups in the California area makes it unlikely that a hospital-based service program will develop within the area, similar to other IHS areas where the federal government has built, staffed and maintained hospitals and satellite clinics on Indian reservations.

Tribal programs will continue to rely on private and public hospitals to meet inpatient and emergency needs. Some tribal health program physicians have privileges at local hospitals and follow their patients through the local hospital system. Otherwise, the patients are referred to private physicians using Contract Health Services (CHS) funding, as well as other alternate resources. Most programs have not developed laboratory, pharmacy or x-ray specialties, so these services are purchased from the private sector through CHS funding or other tribal resources.