California Code, Family Code - FAM § 3764

(a) A health insurance coverage assignment order does not become effective until 20 days after service by the applicant of the assignment order on the employer.

(b) Within 10 days after service of the order, the employer or other person providing health insurance to the obligor shall deliver a copy of the order to the obligor, together with a written statement of the obligor's rights and the relevant procedures under the law to move to quash the order.

(c) Service of a health insurance coverage assignment order on any employer or other person providing health insurance may be made by first class mail in the manner prescribed in Section 1013 of the Code of Civil Procedure.