California is one of the largest health insurance markets in the United States as many companies offer medical insurance plans in the state. In order to offer insurance in the state, a company must have a license from the state of California. This is a highly regulated process in order to ensure that insurance carriers have substantial assets and the necessary infrastructure to offer health insurance. General insurance companies like Aetna, New York Life, Prudential charge higher premiums. These general carriers do not have any specialized delivery mechanisms and usually third parties administer their plans. Specialized insurance giants like Blue Cross and Blue Shield are able to keep costs down with local delivery infrastructure and therefore offer lower premiums to the consumers. Health Maintenance Organizations (HMO) such as Kaiser and HealthNet maintain premiums even lower than the specialists and therefore, have developed a giant share of the market. HMO organizations manage to have such low premiums as they intervene in the health care delivery process as well. In some cases, for instance where carriers run their own delivery centers in California, as Kaiser does, it becomes quite possible to offer such inexpensive rates.

Medical insurance has multiple components and can be underwritten by specialized providers. Dental and vision insurance plans are some examples of this specialized underwriting. The terms of these plans vary widely as do their underwriting guidelines. Therefore, consumers have to be careful about the kind of plan they choose. There are also specialized carriers offering packages that specifically cover disability.

For those who cannot afford health coverage but are eligible for medical aid, the State of California provides a state government driven program. The state of California runs its own facilities to deliver medical benefits to medical recipients.