California Code, Insurance Code - INS § 10127.4

(a) Except as provided in subdivisions (b) and (c), no contract that is issued, amended, renewed, or delivered on or after January 1, 1999, between a disability insurer that provides coverage for hospital, medical, or surgical benefits and a health care provider shall contain provisions that prohibit, restrict, or limit the health care provider from advertising.

(b) Nothing in this section shall be construed to prohibit disability insurers from establishing reasonable guidelines in connection with the activities regulated pursuant to this part, including those to prevent advertising that is, in whole or in part, untrue, misleading, deceptive, or otherwise inconsistent with this part or the rules and regulations promulgated thereunder.  For advertisements mentioning a provider's participation in a plan or product line of a disability insurer, nothing in this section shall be construed to prohibit disability insurers from requiring each advertisement to contain a disclaimer to the effect that the provider's services may be covered for some, but not all, plans or product lines of the disability insurer, or that the disability insurer may cover some, but not all, provider services.

(c) Nothing in this section is intended to prohibit provisions or agreements intended to protect service marks, trademarks, trade secrets, or other confidential information or property.  If a health care provider participates in a provider panel or network as a result of a direct contractual agreement with a disability insurer that, in turn, has entered into a direct contractual agreement with another person or entity, pursuant to which insureds and other beneficiaries of that other person or entity may receive covered services from the health care provider, then nothing in this section is intended to prohibit reasonable provisions or agreements in the direct contractual arrangement between the health care provider and the disability insurer that protect the name or trade name of the other person or entity or requires that the health care provider obtain the consent of the disability insurer prior to the use of the name or trade name of the other person or entity in any advertising by the health care provider.

(d) Nothing in this section shall be construed to impair or impede the authority of the commissioner to regulate advertising, disclosure, or solicitation pursuant to this part.