Insurance Code §1369.555

(a) A health benefit plan issuer or pharmacy benefit manager may not require a patient to use the issuer's or manager's affiliated provider in order for the patient to receive the maximum benefit for the service under the patient's health benefit plan. (b) A health benefit plan issuer or pharmacy benefit manager may not offer or implement a health benefit plan that requires or induces a patient to use the issuer's or manager's affiliated provider, including by providing for reduced cost-sharing if the patient uses the affiliated provider. (c) A health benefit plan issuer or pharmacy benefit manager may not solicit a patient or prescriber to transfer a patient prescription to the issuer's or manager's affiliated provider. (d) A health benefit plan issuer or pharmacy benefit manager may not require a pharmacy or durable medical equipment provider that is not the issuer's or manager's affiliated provider to transfer a patient's prescription to the issuer's or manager's affiliated provider without the prior written consent of the patient.