Tex. Education Code § 29.3521

(a) In the comptroller's legislative appropriations request for each state fiscal biennium, the comptroller shall state the amount of money necessary for the biennium to provide the amount specified under Section 29.361 for each:

(1) participating child;

(2) child on the waiting list maintained by the comptroller under Section 29.356(f) on the January 1 preceding the biennium; and

(3) child who is a sibling of a participating child and is eligible for the program under Section 29.355 for the first time during that biennium.

(b) For purposes of Subsection (a), the comptroller shall specify the amount described by that subsection for the first state fiscal year of the biennium and estimate the amount required for the second state fiscal year of the biennium.

(c) Notwithstanding the amount stated in the comptroller's legislative appropriations request under Subsection (a), the amount appropriated for purposes of the program for a state fiscal biennium must be established by the legislature by appropriation for that biennium.

(c-1) Notwithstanding any other law, for the state fiscal biennium beginning September 1, 2025, the amount spent for purposes of the program may not exceed $1 billion. This subsection expires September 1, 2027.

(d) Notwithstanding any other provision of this subchapter, for each school year, the total amount of money spent for purposes of participation in the program by children described by Section 29.356(b)(2)(D) may not exceed 20 percent of the amount of money appropriated from the program fund for that school year. In allocating money under the program in accordance with this subsection, the comptroller shall ensure children who were enrolled in a school district or open-enrollment charter school for at least 90 percent of the preceding school year are prioritized.