Tex. Health & Safety Code § 612.005
(b) If a supplementary agreement requires or contemplates the use of an institution or facility of this state or requires or contemplates the provision of a service by this state, the supplementary agreement does not take effect until approved by the head of the department or agency:
Added by Acts 1991, 72nd Leg., ch. 76, Sec. 1, eff. Sept. 1, 1991.