40 ILCS 5/17-106
"Contributor", "member" or "teacher": All members of the teaching force of the city, including principals, assistant principals, the general superintendent of schools, deputy superintendents of schools, associate superintendents of schools, assistant and district superintendents of schools, members of the Board of Examiners, all other persons whose employment requires a teaching certificate issued under the laws governing the certification of teachers, any educational staff employed in a contract school operating pursuant to an agreement with the Board of Education who is employed in a position requiring certification or licensure under the School Code (excluding all managerial, supervisory, and confidential employees) and is required to or elects to participate pursuant to Section 17-134.2, any educational, administrative, professional, or other staff employed in a charter school operating in compliance with the Charter Schools Law who is certified under the law governing the certification of teachers, and employees of the Board, but excluding persons contributing concurrently to any other public employee pension system in Illinois for the same employment or receiving retirement pensions under another Article of this Code for that same employment, persons employed on an hourly basis (provided that an Employer may not reclassify a non-hourly employee as an hourly employee for the purpose of evading or avoiding its obligations under this Article), and persons receiving pensions from the Fund who are employed temporarily by an Employer and not on an annual basis.
All teachers or staff regardless of their position shall presumptively be participants in the Fund, unless the Employer establishes to the satisfaction of the Board that an individual certified teacher or staff member is not working as a teacher or administrator directly or indirectly with the Charter School. Any certified teacher or staff employed by a corporate or non-profit entity engaged in the administration of a charter school shall presumptively be a participant in the Fund, unless the organization establishes to the satisfaction of the Board that an individual certified teacher or staff member is not working as a teacher or administrator directly or indirectly with the Charter School.
In the case of a person who has been making contributions and otherwise participating in this Fund prior to the effective date of this amendatory Act of the 91st General Assembly, and whose right to participate in the Fund is established or confirmed by this amendatory Act, such prior participation in the Fund, including all contributions previously made and service credits previously earned by the person, are hereby validated.
The changes made to this Section and Section 17-149 by this amendatory Act of the 92nd General Assembly apply without regard to whether the person was in service on or after the effective date of this amendatory Act, notwithstanding Sections 1-103.1 and 17-157.
40 ILCS 5/17-106