California Code, Health and Safety Code - HSC § 1357.51

(b)(1) A nongrandfathered health benefit plan for individual coverage shall not impose any preexisting condition provision or waivered condition provision upon any enrollee.

(2) A grandfathered health benefit plan for individual coverage shall not exclude coverage on the basis of a waivered condition provision or preexisting condition provision for a period greater than 12 months following the enrollee's effective date of coverage, nor limit or exclude coverage for a specific enrollee by type of illness, treatment, medical condition, or accident, except for satisfaction of a preexisting condition provision or waivered condition provision pursuant to this article. Waivered condition provisions or preexisting condition provisions contained in individual grandfathered health benefit plans may relate only to conditions for which medical advice, diagnosis, care, or treatment, including use of prescription drugs, was recommended or received from a licensed health practitioner during the 12 months immediately preceding the effective date of coverage.

(3) In determining whether a preexisting condition provision or a waivered condition provision applies to an individual under this subdivision, a plan shall credit the time the individual was covered under creditable coverage, provided that the individual becomes eligible for coverage under the succeeding plan contract within 62 days of termination of prior coverage and applies for coverage under the succeeding plan within the applicable enrollment period.