California Code, Labor Code - LAB § 4603.3

(1) A statement of the items or procedures billed and the amounts requested by the provider to be paid.

(2) The amount paid.

(3) The basis for any adjustment, change, or denial of the item or procedure billed.

(4) The additional information required to make a decision for an incomplete itemization.

(5) If a denial of payment is for some reason other than a fee dispute, the reason for the denial.

(6) Information on whom to contact on behalf of the employer if a dispute arises over the payment of the billing. The explanation of review shall inform the medical provider of the time limit to raise any objection regarding the items or procedures paid or disputed and how to obtain an independent review of the medical bill pursuant to Section 4603.6.