In this title the following words have the meanings indicated. “Eligible employee” means a member of the Employees’ Pension System or the Employees’ Retirement System who is subject to Selection C (Combination Formula) as provided in § 22-221 of this article, other than: an employee of a participating governmental unit or a former participating governmental unit that has withdrawn; or a member of the Employees’ Pension System who transferred from the Employees’ Retirement System after April 1, 1998. “Eligible employee” includes: a member of the Employees’ Pension System who contributes to a State supplemental plan authorized by an employing institution as defined in § 30-101 of this article; or a member of the Employees’ Pension System who is an employee of the Northeast Maryland Waste Disposal Authority. “Optional Defined Contribution System” means the system established under § 32-201 of this title. “Participating employee” means an eligible employee who participates in the Optional Defined Contribution System. “State supplemental plan” means a plan qualified under the Internal Revenue Code and: administered by the Supplemental Board; or authorized for eligible employees by an employing institution as defined in § 30-101 of this article. “State supplemental plan” includes: a salary reduction plan qualified under § 401(k) of the Internal Revenue Code; a tax sheltered annuity plan qualified under § 403(b) of the Internal Revenue Code; a deferred compensation plan qualified under § 457 of the Internal Revenue Code; or a plan qualified under § 401(a) of the Internal Revenue Code. “Supplemental Board” means the State Board of Trustees of the Maryland State Employees Supplemental Retirement Plans established under § 35–201 of this article.