California Code, Welfare and Institutions Code - WIC § 14132.23

(a)(1) Except as set forth in paragraph (2), and notwithstanding any other provision of law or regulation, the active and retentive phases of orthodontic treatment covered under the Medi-Cal program shall be reimbursed on a quarterly basis, as determined by dividing the sum of the authorized treatment allowances by the estimated number of three-month periods that the patient's treatment will require, subject to the department's utilization controls.

(2) The retentive phase of orthodontic treatment shall be reimbursed pursuant to paragraph (1) only until the department implements the Code on Dental Procedures and Nomenclature, as published by the American Dental Association in its Current Dental Terminology manual, at which time paragraph (1) shall not apply to retentive phase orthodontic services that are covered under the Medi-Cal program.