In this chapter, "plan issuer" means:
(1) a health insurer, including a life, health, and accident insurer, a health and accident insurer, a health maintenance organization, and any other person operating under Chapter 841, 842, 843, 884, 885, 982, or 1501 who is authorized to issue, issue for delivery, or deliver insurance policies, certificates, contracts, or evidences of coverage in this state;
(2) an approved nonprofit health corporation that holds a certificate of authority issued under Chapter 844; or
(3) an insurer authorized by the department to write workers' compensation insurance in this state.