Texas Government Code - GOV'T § 824.201. Application for Service Retirement Benefits

(a) A member may apply for a service retirement annuity by filing a written application for retirement with the board of trustees.

(b) At any time before the retirement system makes the first annuity payment or the first annuity payment becomes due, a member may, by filing written notice with the board of trustees, revoke the member's application for retirement or make, revoke, or change a selection of an optional service retirement annuity available as provided by Section 824.204.

(c) Except as specifically provided by this subtitle, a retiree may not revoke a retirement nor make, revoke, or change a selection of an optional service retirement annuity.