Tex. Ins. Code § 441.002
In this chapter, unless the purposes of this chapter clearly require or the context clearly indicates another meaning, "insurer" means a person, organization, or company, regardless of whether the person or entity is authorized or admitted, that engages in the business of insurance or that acts as a principal or agent of a person, organization, or company engaged in the business of insurance. The term includes a stock insurance company, reciprocal or interinsurance exchange, Lloyd's plan, fraternal benefit society, stipulated premium company, title insurance company, and mutual insurance company of any kind, including a statewide mutual assessment company, local mutual aid association, burial association, county mutual insurance company, and farm mutual insurance company.
Tex. Ins. Code § 441.002