Cal. Penal Code § 4011

(a) When it is made to appear to any judge by affidavit of the sheriff or other official in charge of county correctional facilities or district attorney and oral testimony that a prisoner confined in any city or county jail within the jurisdiction of the court requires medical or surgical treatment necessitating hospitalization, which treatment cannot be furnished or supplied at such city or county jail, the court in its discretion may order the removal of such person or persons from such city or county jail to the county hospital in such county; provided, if there is no county hospital in such county, then to any hospital designated by such court; and it shall be the duty of the sheriff or other official in charge of county correctional facilities to maintain the necessary guards, who may be private security guards, for the safekeeping of such prisoner, the expense of which shall be a charge against the county.
(b) The cost of such medical services and such hospital care and treatment shall be charged against the county subject to subdivisions (c) and (d), in the case of a prisoner in or taken from the county jail, or against the city in the case of a prisoner in or taken from the city jail, and the city or county may recover the same by appropriate action from the person so served or cared for, or any person or agency responsible for his care and maintenance. If the prisoner is in the county jail under contract with a city or under some other arrangement with the city to keep the city prisoner in the county jail, then the city shall be charged, subject to subdivisions (c) and (d), for the prisoner’s care and maintenance with the same right of recovery against any responsible person or any other agency.
(c) When such prisoner is poor and indigent the cost of such medical services and such hospital care and treatment shall, in the case of persons removed from the city jail be paid out of the general fund of such city, and in the case of persons removed from the county jail to a hospital other than a county hospital, such cost shall be paid out of the general fund of such county or city and county. In the case of city jail prisoners removed to the county hospital, the cost of such hospital care and treatment to be paid by the city to the county, shall be the rate per day fixed by the board of supervisors of such county. Such board of supervisors may, but need not, fix different rates for different classes of patients, or for different wards, and any and all such rates may be changed by such board of supervisors at any time, but shall at all times approximate as nearly as may be, the average actual cost to the county of such hospital care and treatment either in such wards or for such classes of patients or otherwise.
(d) In the event such prisoner is financially able to pay for his care, support and maintenance, the medical superintendent of such hospital other than a county hospital may, with the approval of such judge, enter into a special agreement with such person, or with his relatives or friends, for his care, support, maintenance, and other hospital expenses.
Any prisoner may decline such care or treatment and provide other care and treatment for himself at his own expense.