Tex. Ins. Code § 1305.252

If requested by the commissioner or the commissioner's representative, each provider, provider group, or third party with which the network has contracted to provide health care services or any other services delegated to the network by an insurance carrier shall make available for examination by the department that portion of the books and records of the provider, provider group, or third party that is relevant to the relationship with the network of the provider, provider group, or third party.