Tex. Gov't Code § 844.3051
(a) The retirement annuity of a disability retiree may not be terminated under this subchapter after the earlier of:
Added by Acts 2001, 77th Leg., ch. 122, Sec. 33, eff. Dec. 31, 2001.
Acts 2007, 80th Leg., R.S., Ch. 873 (H.B. 1587), Sec. 45, eff. January 1, 2008.