Cal. Health & Safety Code § 1389.5
(b) At least once each year, the health care service plan shall permit an individual who has been covered for at least 18 months under an individual plan contract to transfer, without medical underwriting, to any other individual plan contract offered by that same health care service plan that provides equal or lesser benefits, as determined by the plan.
“Without medical underwriting” means that the health care service plan shall not decline to offer coverage to, or deny enrollment of, the individual or impose any preexisting condition exclusion on the individual who transfers to another individual plan contract pursuant to this section.
(e) The requirements of this section do not apply to the following:
(g)