(a) On request by the group policyholder, any group accident and health insurance policy may provide that all or any portion of any indemnities provided by any policy on account of hospital, nursing, medical, or surgical services may be paid, at the insurer's option, directly to the hospital or person rendering such services, but the policy may not require that the service be rendered by a particular hospital or person.
(b) Payment so made shall discharge the insurer's obligation with respect to the amount of insurance paid.