34 Tex. Admin. Code § 29.15
A person who has retired may not be employed in any position in a public school during the first month following that person's effective date of retirement, or during the first two months following an effective date of retirement which uses the Texas Government Code, §824.002(d) (this is the May 31-June 15 rules described in §29.14 of this title (relating to Eligibility for Retirement at the End of May)). Employment in any capacity revokes the retirement and requires a return of any benefits received under the original retirement.
Source Note:The provisions of this §29.15 adopted to be effective January 1, 1976; amended to be effective December 4, 1985, 10 TexReg 4538; amended to be effective September 29, 1989, 14 TexReg 4784.