Insurer shall pay for services rendered within 30 working days after receipt of a complete claim or 45 working days if the health care service plan is a health maintenance organization. If claim is denied, insurer must provide what information is required to process the claim. If an uncontested claim is not paid, interest shall accrue at 15% per annum.

Link to Existing Law: CA Health & Safety Code Division 2 Ch. 2.2 Article 5 Section 1371.35

While PBMs are not specifically mentioned, they are likely included as an agent for insurance companies.