Texas Government Code - GOV'T § 812.204. Notice

(a) Before a retiree begins work in a position included in the employee class of membership, the retiree and the head of the department, commission, board, agency, or institution at which the retiree will resume state service each shall notify the retirement system in writing of the retiree's name, the taking of a position, and the projected dates of service.

(b) Before a retiree from the elected class of membership takes the oath of office for a position included in that class, the retiree shall notify the retirement system in writing of the taking of a position and the projected dates of service.