19-13-701. Eligibility for service retirement. (1) Subject to a member's right to a refund of the member's accumulated contributions under Title 19, chapter 2, part 6, the following members are eligible to receive a nonforfeitable service retirement benefit under 19-13-704:

(a) a member who has completed 20 years or more of membership service; or

(b) a vested member who terminates service before completing 20 years of service and applies for a service retirement upon reaching age 50.

(2) For purposes of compliance with section 411 of the Internal Revenue Code, 26 U.S.C. 411, a member described in subsection (1)(b) is treated as having attained normal retirement age and has a nonforfeitable right to the member's service retirement.