California Code, Government Code - GOV § 19996.32

Any state employee, or legislative employee, who is a state miscellaneous or industrial member working standard hours on a full-time basis, other than a university member, of the Public Employees' Retirement System and who is eligible to retire pursuant to Section 20953 may elect to participate in reduced worktime for partial service retirement pursuant to this article, provided that the participation may be modified only pursuant to Section 19996.37.