Cal. Gov't Code § 22947

(a) A health benefits trust may assert a lien for health benefits paid on behalf of a participant against any settlement with, or arbitration award or judgment against, a third party. No lien asserted by a health benefits trust under this section may exceed the amount actually paid by the trust to any treating medical provider.
(b) The participant, if not represented by an attorney, or the participant’s attorney, shall immediately send, by certified mail, written notice of the existence of any claim or action against a third party, to the following:
1. (1) The health benefits trust.
2. (2) A hospital or any hospital-affiliated health facility, as defined in Section 1250 of the Health and Safety Code, that is known to have provided health care services to the participant.
(c) If medical costs are paid by the health benefits trust, contract providers may not assert an independent lien against the participant. Contract providers who agree, by contract, to a specified rate may not seek to recover an amount that exceeds the contracted rate against the participant.
This subdivision is not applicable to a lien for hospital services pursuant to Chapter 4 (commencing with Section 3045.1) of Title 14 of Part 4 of Division 3 of the Civil Code.
(d) If the participant engaged an attorney, the lien for health services asserted by a health benefits trust under subdivision (a) may not exceed the lesser of the actual amount paid by the trust or one-third of the moneys due to the participant under any final judgment, compromise, arbitration, or settlement agreement.
(e) If the participant did not engage an attorney, the lien for health services asserted by the health benefits trust under subdivision (a) may not exceed the lesser of the actual amount paid by the trust or one-half of the moneys due to the participant under any final judgment, compromise, arbitration, or settlement agreement.
(f) If a final judgment includes a special finding by a judge, jury, or arbitrator that the participant was partially at fault, the lien asserted by the health benefits trust shall be reduced by the same comparative fault percentage by which the participant’s recovery was reduced.
(g) The lien asserted by the health benefits trust shall be subject to pro rata reduction, commensurate with the participant’s reasonable attorney’s fees and costs, in accordance with the common fund doctrine.
(h) The court or arbitrator may also take into account the obligation, if any, of the health benefits trust to make future medical payments on behalf of the participant for the medical condition that gave rise to the claim against the third party.
(i) The provisions of this section may not be admitted into evidence nor given in any instruction in any civil action or proceeding between a participant and a third party.