"Membership service": Service rendered while a member of the System for which credit is allowable under this Article, and for persons entering service on or after January 1, 1984, or after July 1, 1982 in the case of an emergency or temporary employee as defined in Sections 8b.8 and 8b.9 of the Personnel Code, service rendered as an employee before becoming a member, if credit for such service is received pursuant to Section 14-104.5.
40 ILCS 5/14-103.13