(a) In this section, “investigational or experimental service or device” means a health care treatment, service, or device for which there is early, developing scientific or clinical evidence demonstrating the potential efficacy of the treatment, service, or device but that is not yet broadly accepted as the prevailing standard of care.
(b) The commissioner by rule shall specify which health care treatments and services require express preauthorization or concurrent review by the insurance carrier. Treatments and services for a medical emergency do not require express preauthorization.

(c) The commissioner’s rules adopted under this section must provide that preauthorization and concurrent review are required at a minimum for:
(1) spinal surgery, as provided by Section 408.026;
(2) work-hardening or work-conditioning services;
(3) inpatient hospitalization, including any procedure and length of stay;
(4) physical and occupational therapy;
(5) outpatient or ambulatory surgical services, as defined by commissioner rule; and
(6) any investigational or experimental services or devices.
(c-1) Notwithstanding Subsection (c)(2), the commissioner by rule may exempt from preauthorization and concurrent review work-hardening or work-conditioning services provided by a health care facility that is credentialed by an organization designated by commissioner rule.
(d) The insurance carrier is not liable for those specified treatments and services requiring preauthorization unless preauthorization is sought by the claimant or health care provider and either obtained from the insurance carrier or ordered by the commissioner.
(e) If a specified health care treatment or service is preauthorized as provided by this section, that treatment or service is not subject to retrospective review of the medical necessity of the treatment or service.
(f) The division may not prohibit an insurance carrier and a health care provider from voluntarily discussing health care treatment and treatment plans and pharmaceutical services, either prospectively or concurrently, and may not prohibit an insurance carrier from certifying or agreeing to pay for health care consistent with those agreements. The insurance carrier is liable for health care treatment and treatment plans and pharmaceutical services that are voluntarily preauthorized and may not dispute the certified or agreed-on preauthorized health care treatment and treatment plans and pharmaceutical services at a later date.