The board of trustees may not contract for or provide a coverage plan that:
(1) excludes or limits coverage or services for acquired immune deficiency syndrome, as defined by the Centers for Disease Control and Prevention of the United States Public Health Service, or human immunodeficiency virus infection;
(2) provides coverage for serious mental illness that is less extensive than the coverage provided for any physical illness; or
(3) may provide coverage for prescription drugs to assist in stopping smoking at a lower benefit level than is provided for other prescription drugs.