Tex. Human Resources Code § 32.029

(a) The commission may prescribe a method of payment for medical assistance claims by establishing a direct vendor payment program that is administered by the commission, or by an insurance plan, a hospital or medical service plan, or any other health service plan authorized to do business in the state, or by a combination of those plans.

(b) The commission may use any fiscal intermediary, method of payment, or combination of methods it finds most satisfactory and economical. The commission may make whatever changes it finds necessary from time to time to administer the program in an economical and equitable manner consistent with simplicity of administration and the best interest of the recipients of medical assistance.

(c) If the commission elects to make direct vendor payments, the payments shall be made by vouchers and warrants drawn by the comptroller on the proper account. The commission shall furnish the comptroller with a list of those vendors entitled to payments and the amounts to which each is entitled. When the warrants are drawn, they must be delivered to the commission, which shall supervise the delivery to vendors.

(d) If at any time state funds are not available to fully pay all claims for medical assistance, the executive commissioner shall prorate the claims.

(e) The commission or its designee must notify providers of health care services in clear and concise language of the status of their claims on any claim not paid or denied within 30 days of receipt by the payor.