Cal. INS § 674.6

(a) No insurer issuing policies of insurance subject to Section 674.5 or 675 shall cease to offer any particular line of coverage without prior notification to the commissioner.

(b) Except as provided in Section 674.9, an insurer shall notify the department at least 60 days prior to the date it intends to withdraw wholly or substantially from a line of (1) commercial liability insurance, (2) any insurance defined in Section 660 or 675 when coverage is provided by a separate rider or endorsement for an activity for which the insured receives compensation, a stipend, or remuneration of any kind for the activity and then only to the extent of the coverage, (3) any other insurance defined in Section 660, or (4) any insurance issued to an individual or individuals covering a risk not arising from a business or commercial activity. Upon receipt of the notice, the commissioner may request and review additional information, as deemed necessary, and investigate the market conditions to determine whether that insurance may become not readily available in the voluntary insurance market as a result of the withdrawal.

(c) For purposes of this section, “intent to substantially withdraw” means an insurer’s intent to nonrenew in excess of 50 percent of its current policyholders in the line of coverage upon their next renewal.

(d) The commissioner shall adopt appropriate rules, regulations, and standards for purposes of implementing this section.

(e) Any insurer that has notified the commissioner pursuant to subdivision (b) shall (1) notify the commissioner within 10 days after the date given in the withdrawal notice if the insurer does not in fact withdraw that line of insurance from the market, or (2) notify the commissioner within 10 days after reentry if the insurer reenters that line after the withdrawal.