California Code, Labor Code - LAB § 4903.4

(a) If a dispute arises concerning a lien for expenses incurred by or on behalf of the injured employee as provided by Article 2 (commencing with Section 4600) of Chapter 2 of Part 2, the appeals board may resolve the dispute in a separate proceeding, which may include binding arbitration upon agreement of the employer, lien claimant, and the employee, if the employee remains a party to the dispute, according to the rules of practice and procedure.

(b) If the dispute is heard at a separate proceeding it shall be calendared for hearing or hearings as determined by the appeals board based upon the resources available to the appeals board and other considerations as the appeals board deems appropriate and shall not be subject to Section 5501.5.