Cal. Lab. Code § 4903.8

(a)
1. (1) Any order or award for payment of a lien filed pursuant to subdivision (b) of Section 4903 shall be made for payment only to the person who was entitled to payment for the expenses as provided in subdivision (b) of Section 4903 at the time the expenses were incurred, who is the lien owner, and not to an assignee unless the person has ceased doing business in the capacity held at the time the expenses were incurred and has assigned all right, title, and interest in the remaining accounts receivable to the assignee.
2. (2) All liens filed pursuant to subdivision (b) of Section 4903 shall be filed in the name of the lien owner only, and no payment shall be made to any lien claimant without evidence that he or she is the owner of that lien.
3. (3) Paragraph (1) does not apply to an assignment that was completed prior to January 1, 2013, or that was required by a contract that became enforceable and irrevocable prior to January 1, 2013. This paragraph is declarative of existing law.
4. (4) For liens filed after January 1, 2017, the lien shall not be assigned unless the person has ceased doing business in the capacity held at the time the expenses were incurred and has assigned all right, title, and interest in the remaining accounts receivable to the assignee. The assignment of a lien, in violation of this paragraph is invalid by operation of law.
(b) If there has been an assignment of a lien, either as an assignment of all right, title, and interest in the accounts receivable or as an assignment for collection, a true and correct copy of the assignment shall be filed and served.
1. (1) If the lien is filed on or after January 1, 2013, and the assignment occurs before the filing of the lien, the copy of the assignment shall be served at the time the lien is filed.
2. (2) If the lien is filed on or after January 1, 2013, and the assignment occurs after the filing of the lien, the copy of the assignment shall be served within 20 days of the date of the assignment.
3. (3) If the lien is filed before January 1, 2013, the copy of the assignment shall be served by January 1, 2014, or with the filing of a declaration of readiness or at the time of a lien hearing, whichever is earliest.
(c) If there has been more than one assignment of the same receivable or bill, the appeals board may set the matter for hearing on whether the multiple assignments constitute bad-faith actions or tactics that are frivolous, harassing, or intended to cause unnecessary delay or expense. If so found by the appeals board, appropriate sanctions, including costs and attorney’s fees, may be awarded against the assignor, assignee, and their respective attorneys.
(d) At the time of filing of a lien on or after January 1, 2013, or in the case of a lien filed before January 1, 2013, at the earliest of the filing of a declaration of readiness, a lien hearing, or January 1, 2014, supporting documentation shall be filed including one or more declarations under penalty of perjury by a natural person or persons competent to testify to the facts stated, declaring both of the following:
1. (1) The services or products described in the bill for services or products were actually provided to the injured employee.
2. (2) The billing statement attached to the lien truly and accurately describes the services or products that were provided to the injured employee.
(e) A lien submitted for filing on or after January 1, 2013, for expenses provided in subdivision (b) of Section 4903, that does not comply with the requirements of this section shall be deemed to be invalid, whether or not accepted for filing by the appeals board, and shall not operate to preserve or extend any time limit for filing of the lien.
(f) This section shall take effect without regulatory action. The appeals board and the administrative director may promulgate regulations and forms for the implementation of this section.