Cal. Lab. Code § 4603.2
(a)
(b)
(1)
(2) Except as provided in subdivision (d) of Section 4603.4, or under contracts authorized under Section 5307.11, payment for medical treatment provided or prescribed by the treating physician selected by the employee or designated by the employer shall be made at reasonable maximum amounts in the official medical fee schedule, pursuant to Section 5307.1, in effect on the date of service. Payments shall be made by the employer with an explanation of review pursuant to Section 4603.3 within 45 days after receipt of each separate itemization of medical services provided, together with any required reports and any written authorization for services that may have been received by the physician. If the itemization or a portion thereof is contested, denied, or considered incomplete, the physician shall be notified, in the explanation of review, that the itemization is contested, denied, or considered incomplete, within 30 days after receipt of the itemization by the employer. An explanation of review that states an itemization is incomplete shall also state all additional information required to make a decision. A properly documented list of services provided and not paid at the rates then in effect under Section 5307.1 within the 45-day period shall be paid at the rates then in effect and increased by 15 percent, together with interest at the same rate as judgments in civil actions retroactive to the date of receipt of the itemization, unless the employer does both of the following:
(B) Advises, in an explanation of review pursuant to Section 4603.3, the physician, or another provider of the items being contested, the reasons for contesting these items, and the remedies available to the physician or the other provider if the physician or provider disagrees. In the case of an itemization that includes services provided by a hospital, outpatient surgery center, or independent diagnostic facility, advice that a request has been made for an audit of the itemization shall satisfy the requirements of this paragraph.
An employer’s liability to a physician or another provider under this section for delayed payments shall not affect its liability to an employee under Section 5814 or any other provision of this division.
(5)
(d)
(2)
(e)
(1) If the provider disputes the amount paid, the provider may request a second review within 90 days of service of the explanation of review or an order of the appeals board resolving the threshold issue as stated in the explanation of review pursuant to paragraph (5) of subdivision (a) of Section 4603.3. The request for a second review shall be submitted to the employer on a form prescribed by the administrative director and shall include all of the following: