1. Any person, duly certified under the law governing the certification of teachers, employed full time as a teacher by the division of youth services prior to August 13, 1986, who did not become a member of the Missouri state employees’ retirement system under section 104.342 is a member of the public school retirement system of Missouri. Any such person who becomes a member before the end of the school year next following July 18, 1948, may claim and receive credit for prior service. The contributions required to be made by the member’s employer shall be paid from appropriations to the institution by which the member is employed.

2. Any person, duly certified under the law governing the certification of teachers, employed full time as a teacher by a division of the state department of social services prior to August 13, 1986, who did not become a member of the Missouri state employees’ retirement system under section 104.342, who renders services in a school whose standards of education are set and which is supervised by a public school officer of the county in which the school is located, by the department of elementary and secondary education or by the coordinating board for higher education is a member of the public school retirement system of Missouri. Any such member who becomes a member before the end of the school year next following August 29, 1953, may claim and receive credit for prior service.

3. Any person, duly certified under the law governing the certification of teachers, employed full time as a teacher by the section of inmate education of the department of corrections prior to August 13, 1986, who did not become a member of the Missouri state employees’ retirement system under section 104.342 is a member of the public school retirement system of Missouri. Any such person who becomes a member before the end of the school year next following August 29, 1959, may claim and receive credit for prior service. For purposes of this subsection “prior service” means service rendered by a member of the retirement system before the system becomes operative with respect to persons employed by the section of inmate education, and may include service rendered by a member of the Armed Forces during a period of war, if the member was a teacher at the time he was inducted, for which credit has been approved by the board of trustees.

4. Any person, duly certificated under the law governing the certification of teachers, employed full time by any statewide nonprofit educational association or organization serving on an educational professional basis through its membership the active members of the public school retirement system of Missouri or the public school districts maintaining high schools in this state, may be a member of the public school retirement system of Missouri. Any such person who becomes a member before July 1, 1955, may claim and receive credit for prior service. The contributions required to be made by the member’s employer shall be paid by the association or organization. After June 30, 2010, no additional nonprofit educational associations or organizations may have their employees become members of the public school retirement system of Missouri or the public education employee retirement system of Missouri.

5. Any person, duly certificated under the law governing the certification of teachers, employed full time, and whose duties include participation in the educational program of the department of mental health, in either a teaching or supervisory teaching capacity prior to August 13, 1986, who did not become a member of the Missouri state employees’ retirement system under section 104.342 shall, after August 7, 1969, be a member of the public school retirement system, but any such person whose employment with the department of mental health commenced prior to August 7, 1969, may elect not to become a member by so notifying the department of mental health in writing within thirty days after August 7, 1969.