California Code, Health and Safety Code - HSC § 123195

(a) A contract provided for by this chapter shall not be required to cover a preexisting medical condition of the resident during the first 10 months the resident is covered by catastrophic health insurance provided under this chapter. Charges for a preexisting condition shall not apply toward the deductible during the first 10 months of coverage. Charges for other conditions during that initial period shall apply toward the deductible.

(b) The contract shall also prohibit the insurer from discriminating against prospective insureds in their underwriting practices on the basis of demographic factors, such as age, or preexisting medical conditions.