Cal. Government Code § 21025.5

(a) “Public service” with respect to a school member or a retired school member also means service rendered on or after June 30, 1977, and prior to June 30, 1982, to an independent data processing center formed pursuant to former Article 2 (commencing with Section 10550) of Chapter 6 of Part 7 of Title 1 of the Education Code, as it read on December 31, 1990, if all of the following conditions are met: (1) The member was a school member prior to employment with the independent data processing center. (2) The member returned to school employment following termination of his or her employment with the independent data processing center. (3) The member received a refund of the contributions he or she made to the system during his or her employment with the independent data processing center. (b) A retirement allowance of a retired school member who elects to receive service credit for public service pursuant to this section shall be increased only with respect to the allowance payable on and after the first day of the month following the date the election is received. (c) A member may elect to receive credit for public service pursuant to this section at any time. (d) Any member electing to receive credit for service under this section shall make the contributions as specified in Sections 21050 and 21052.