(1) On and after July 1, 1977, an individual or group policy of sickness, health, or accident insurance or small group sickness and accident insurance delivered or issued for delivery to any person in this state that provides coverage for behavioral or mental health disorders or intellectual and developmental disabilities must not exclude or be construed to diminish benefits for the payment of the direct costs, related directly to the treatment of such behavioral or mental health disorders or intellectual and developmental disabilities, provided by a state institution, including community clinics and centers providing services for persons with behavioral or mental health disorders or intellectual and developmental disabilities if the charges for treatment of such behavioral or mental health disorders or intellectual and developmental disabilities are customarily charged to nonindigent patients by the state institution.
(2) Any policy issued on or after July 1, 1977, on a form approved prior to said date, containing any provisions in conflict with the provisions of this section shall be in effect only if there is attached to such policy at the time of issue a rider or endorsement amending such policy to conform to the provisions of this section.