34 Tex. Admin. Code § 25.41
Persons who have been required by law to be members of the Teacher Retirement System of Texas or who have service or compensation on which contributions were required but who have not made the required deposits shall start making deposits immediately for current service and may make payment of the actuarial cost for previous service or compensation under §25.43 of this title (Cost for Unreported Service or Compensation).
Source Note:The provisions of this §25.41 adopted to be effective January 1, 1976; amended to be effective March 12, 2003, 28 TexReg 2095; amended to be effective March 8, 2007, 32 TexReg 1079; amended to be effective April 1, 2011, 36 TexReg 1832; amended to be effective September 1, 2011, 36 TexReg 5370.