28 Tex. Admin. Code § 21.2801
The purpose of this subchapter is to specify the definitions and procedures necessary to implement Insurance Code Chapters 843 and 1301 relating to clean claims and prompt payment of physician and provider claims. This subchapter applies to all nonelectronic and electronic claims submitted by contracted physicians or providers for services or benefits provided to insureds of preferred provider carriers, insureds of exclusive provider carriers, and enrollees of health maintenance organizations. The subchapter also has limited applicability to noncontracted physicians and providers. This subchapter does not apply to an exclusive provider benefit plan regulated under Chapter 3, Subchapter KK of this title (relating to Exclusive Provider Benefit Plan) written by an insurer under a contract with the Health and Human Services Commission to provide services under the Texas Children's Health Insurance Program or Medicaid.
28 Tex. Admin. Code § 21.2801