Tex. Insurance Code § 843.321

(a) A contract between a health maintenance organization and a physician or provider must provide that:

(1) the physician or provider may request a description and copy of the coding guidelines, including any underlying bundling, recoding, or other payment process and fee schedules applicable to specific procedures that the physician or provider will receive under the contract;

(2) the health maintenance organization or the health maintenance organization's agent will provide the coding guidelines and fee schedules not later than the 30th day after the date the health maintenance organization receives the request;

(3) the health maintenance organization or the health maintenance organization's agent will provide notice of changes to the coding guidelines and fee schedules that will result in a change of payment to the physician or provider not later than the 90th day before the date the changes take effect and will not make retroactive revisions to the coding guidelines and fee schedules; and

(4) the contract may be terminated by the physician or provider on or before the 30th day after the date the physician or provider receives information requested under this subsection without penalty or discrimination in participation in other health care products or plans.

(b) A physician or provider who receives information under Subsection (a) may only:

(1) use or disclose the information for the purpose of practice management, billing activities, and other business operations; and

(2) disclose the information to a governmental agency involved in the regulation of health care or insurance.

(c) The health maintenance organization shall, on request of the physician or provider, provide the name, edition, and model version of the software that the health maintenance organization uses to determine bundling and unbundling of claims.

(d) The provisions of this section may not be waived, voided, or nullified by contract.