28 CCR §1300.71(3)(B)

(B) For contracted providers without a written contract and non-contracted providers, except those providing services described in paragraph (C) below: the payment of the reasonable and customary value for the health care services rendered based upon statistically credible information that is updated at least annually and takes into consideration:(1) the provider’s training, qualifications, and length of time in practice; (ii) the nature of the services provided; (iii) the fees usually charged by the provider; (iv) prevailing provider rates charged in the general geographic area in which the services were rendered; (v) other aspects of the economics of the medical provider’s practice that are relevant; and (vi) any unusual circumstances in the case.