Zuniga

*984 As a result of amendments to California's workers' compensation law that took effect in 2013, an injured worker may challenge a decision denying medical treatment by requesting a determination of medical necessity from an independent medical review (IMR) organization. ( Lab. Code, §§ 139.5, 4610.5. 1 ) The IMR organization, which is regulated by the Division of Workers' Compensation of the Department of Industrial Relations (Division) and operates under contract with the administrative director of the Division, designates one or more medical professionals to review pertinent medical records, determine whether the disputed treatment is medically necessary, and prepare a written report including statutorily-required findings to support the reviewer's determination. ( § 139.5, subd. (a)(1), § 4610.6, subds. (a) through (e) ; Cal. Code Regs., tit. 8, § 9792.10.1 et seq. ) The determination of the IMR organization is deemed to be the determination of the administrative director, and is binding on all parties, subject *298 to appeal on narrow statutory grounds. ( § 4610.6, subds. (g) & (h).)

Of significance to the matter before us, the IMR organization is required by statute to…