(a) An insurer that uses a preauthorization process for medical care or health care services shall provide to each preferred provider, not later than the fifth business day after the date a request is made, a list of medical care and health care services that require preauthorization and information concerning the preauthorization process.
(b) If proposed medical care or health care services require preauthorization as a condition of the insurer’s payment to a preferred provider under a health insurance policy, the insurer shall determine whether the medical care or health care services proposed to be provided to the insured are medically necessary and appropriate.

(c) On receipt of a request from a preferred provider for preauthorization, the insurer shall review and issue a determination indicating whether the proposed medical care or health care services are preauthorized. The determination must be issued and transmitted not later than the third calendar day after the date the request is received by the insurer.
(d) If the proposed medical care or health care services involve inpatient care and the insurer requires preauthorization as a condition of payment, the insurer shall review the request and issue a length of stay for the admission into a health care facility based on the recommendation of the patient’s physician or health care provider and the insurer’s written medically accepted screening criteria and review procedures. If the proposed medical or health care services are to be provided to a patient who is an inpatient in a health care facility at the time the services are proposed, the insurer shall review the request and issue a determination indicating whether proposed services are preauthorized within 24 hours of the request by the physician or provider.
(e) An insurer shall have appropriate personnel reasonably available at a toll-free telephone number to respond to requests for a preauthorization between 6 a.m. and 6 p.m. central time Monday through Friday on each day that is not a legal holiday and between 9 a.m. and noon central time on Saturday, Sunday, and legal holidays. An insurer must have a telephone system capable of accepting or recording incoming phone calls for preauthorizations after 6 p.m. central time Monday through Friday and after noon central time on Saturday, Sunday, and legal holidays and responding to each of those calls not later than 24 hours after the call is received.
(f) If an insurer has preauthorized medical care or health care services, the insurer may not deny or reduce payment to the physician or health care provider for those services based on medical necessity or appropriateness of care unless the physician or provider has materially misrepresented the proposed medical or health care services or has substantially failed to perform the proposed medical or health care services.
(g) This section applies to an agent or other person with whom an insurer contracts to perform, or to whom the insurer delegates the performance of, preauthorization of proposed medical or health care services.
(h) The provisions of this section may not be waived, voided, or nullified by contract.