The membership of the retirement system shall consist of the following:

1. (1) All classified personnel shall become members of the retirement system as a condition of their employment.
2. (2) All full-time nonclassified optional personnel regularly employed for more than one (1) year may join the Teachers' Retirement System subject to the rules and regulations adopted pursuant to this act. Subject to the outcome of a private letter ruling request which shall be submitted by the Board to the Internal Revenue Service, the System shall permit full-time nonclassified optional personnel who have ceased to make otherwise required employee contributions after having made an election to become a member of the retirement system to resume employee contributions. No service shall be credited to any such member for any period of time during which employee contributions were not made.
3. (3) All persons who shall become classified personnel or who are regularly employed in any school system as new classified personnel after July 1, 1943, hereof, shall become members of the retirement system as a condition of their employment.
4. (4) All other regular school employees may join the Teachers' Retirement System subject to the rules and regulations as may be adopted by the Board of Trustees of the Teachers' Retirement System.
5. (5) The Board of Trustees may, in its discretion, deny the right to become members to any class of members whose compensation is only partly paid by the state, or who is serving on a temporary or other than per annum basis, and it also may, in its discretion, make optional with members in any such class their individual entrance into the retirement system.
6. (6) Should any member, with less than ten (10) years of teaching service in Oklahoma, in any period of six (6) consecutive years after becoming a member be absent from service more than five (5) years, withdraw his contributions, retire or die, he shall thereupon cease to be a member. The provisions of this paragraph shall not apply to any member of the Teachers' Retirement System who has been a member of such classes of military services as may be approved by the Board of Trustees, until a period of one and one-half (1 1/2) years from date of termination of such service shall have elapsed.

Laws 1969, c. 157, § 3, operative Aug. 2, 1969; Amended by Laws 1970, c. 176, § 2, operative Aug. 2, 1970; Amended by Laws 1976, c. 252, § 4, operative July 1, 1976; Amended by Laws 1978, c. 238, § 3, eff. July 1, 1978; Amended by Laws 1985, c. 180, § 2, eff. July 1, 1985; Amended by Laws 1986, c. 283, § 1, operative July 1, 1986; Amended by Laws 1990, c. 340, § 27, eff. July 1, 1990; Amended by Laws 2001, HB 1754, c. 336, § 1, emerg. eff. July 1, 2001 (superseded document available).