(40 ILCS 5/16-127) (from Ch. 108 1/2, par. 16-127)
    (Text of Section WITH the changes made by P.A. 98-599, which has been held unconstitutional)
    Sec. 16-127. Computation of creditable service.
    (a) Each member shall receive regular credit for all service as a teacher from the date membership begins, for which satisfactory evidence is supplied and all contributions have been paid.
    (b) The following periods of service shall earn optional credit and each member shall receive credit for all such service for which satisfactory evidence is supplied and all contributions have been paid as of the date specified:
        (1) Prior service as a teacher.
        (2) Service in a capacity essentially similar or
    
equivalent to that of a teacher, in the public common schools in school districts in this State not included within the provisions of this System, or of any other State, territory, dependency or possession of the United States, or in schools operated by or under the auspices of the United States, or under the auspices of any agency or department of any other State, and service during any period of professional speech correction or special education experience for a public agency within this State or any other State, territory, dependency or possession of the United States, and service prior to February 1, 1951 as a recreation worker for the Illinois Department of Public Safety, for a period not exceeding the lesser of 2/5 of the total creditable service of the member or 10 years. The maximum service of 10 years which is allowable under this paragraph shall be reduced by the service credit which is validated by other retirement systems under paragraph (i) of Section 15-113 and paragraph 1 of Section 17-133. Credit granted under this paragraph may not be used in determination of a retirement annuity or disability benefits unless the member has at least 5 years of creditable service earned subsequent to this employment with one or more of the following systems: Teachers' Retirement System of the State of Illinois, State Universities Retirement System, and the Public School Teachers' Pension and Retirement Fund of Chicago. Whenever such service credit exceeds the maximum allowed for all purposes of this Article, the first service rendered in point of time shall be considered. The changes to this subdivision (b)(2) made by Public Act 86-272 shall apply not only to persons who on or after its effective date (August 23, 1989) are in service as a teacher under the System, but also to persons whose status as such a teacher terminated prior to such effective date, whether or not such person is an annuitant on that date.
        (3) Any periods immediately following teaching
    
service, under this System or under Article 17, (or immediately following service prior to February 1, 1951 as a recreation worker for the Illinois Department of Public Safety) spent in active service with the military forces of the United States; periods spent in educational programs that prepare for return to teaching sponsored by the federal government following such active military service; if a teacher returns to teaching service within one calendar year after discharge or after the completion of the educational program, a further period, not exceeding one calendar year, between time spent in military service or in such educational programs and the return to employment as a teacher under this System; and a period of up to 2 years of active military service not immediately following employment as a teacher.
        The changes to this Section and Section 16-128
    
relating to military service made by P.A. 87-794 shall apply not only to persons who on or after its effective date are in service as a teacher under the System, but also to persons whose status as a teacher terminated prior to that date, whether or not the person is an annuitant on that date. In the case of an annuitant who applies for credit allowable under this Section for a period of military service that did not immediately follow employment, and who has made the required contributions for such credit, the annuity shall be recalculated to include the additional service credit, with the increase taking effect on the date the System received written notification of the annuitant's intent to purchase the credit, if payment of all the required contributions is made within 60 days of such notice, or else on the first annuity payment date following the date of payment of the required contributions. In calculating the automatic annual increase for an annuity that has been recalculated under this Section, the increase attributable to the additional service allowable under P.A. 87-794 shall be included in the calculation of automatic annual increases accruing after the effective date of the recalculation.
        Credit for military service shall be determined as
    
follows: if entry occurs during the months of July, August, or September and the member was a teacher at the end of the immediately preceding school term, credit shall be granted from July 1 of the year in which he or she entered service; if entry occurs during the school term and the teacher was in teaching service at the beginning of the school term, credit shall be granted from July 1 of such year. In all other cases where credit for military service is allowed, credit shall be granted from the date of entry into the service.
        The total period of military service for which credit
    
is granted shall not exceed 5 years for any member unless the service: (A) is validated before July 1, 1964, and (B) does not extend beyond July 1, 1963. Credit for military service shall be granted under this Section only if not more than 5 years of the military service for which credit is granted under this Section is used by the member to qualify for a military retirement allotment from any branch of the armed forces of the United States. The changes to this subdivision (b)(3) made by Public Act 86-272 shall apply not only to persons who on or after its effective date (August 23, 1989) are in service as a teacher under the System, but also to persons whose status as such a teacher terminated prior to such effective date, whether or not such person is an annuitant on that date.
        (4) Any periods served as a member of the General
    
Assembly.
        (5)(i) Any periods for which a teacher, as defined in
    
Section 16-106, is granted a leave of absence, provided he or she returns to teaching service creditable under this System or the State Universities Retirement System following the leave; (ii) periods during which a teacher is involuntarily laid off from teaching, provided he or she returns to teaching following the lay-off; (iii) periods prior to July 1, 1983 during which a teacher ceased covered employment due to pregnancy, provided that the teacher returned to teaching service creditable under this System or the State Universities Retirement System following the pregnancy and submits evidence satisfactory to the Board documenting that the employment ceased due to pregnancy; and (iv) periods prior to July 1, 1983 during which a teacher ceased covered employment for the purpose of adopting an infant under 3 years of age or caring for a newly adopted infant under 3 years of age, provided that the teacher returned to teaching service creditable under this System or the State Universities Retirement System following the adoption and submits evidence satisfactory to the Board documenting that the employment ceased for the purpose of adopting an infant under 3 years of age or caring for a newly adopted infant under 3 years of age. However, total credit under this paragraph (5) may not exceed 3 years.
        Any qualified member or annuitant may apply for
    
credit under item (iii) or (iv) of this paragraph (5) without regard to whether service was terminated before the effective date of this amendatory Act of 1997. In the case of an annuitant who establishes credit under item (iii) or (iv), the annuity shall be recalculated to include the additional service credit. The increase in annuity shall take effect on the date the System receives written notification of the annuitant's intent to purchase the credit, if the required evidence is submitted and the required contribution paid within 60 days of that notification, otherwise on the first annuity payment date following the System's receipt of the required evidence and contribution. The increase in an annuity recalculated under this provision shall be included in the calculation of automatic annual increases in the annuity accruing after the effective date of the recalculation.
        Optional credit may be purchased under this
    
subsection (b)(5) for periods during which a teacher has been granted a leave of absence pursuant to Section 24-13 of the School Code. A teacher whose service under this Article terminated prior to the effective date of P.A. 86-1488 shall be eligible to purchase such optional credit. If a teacher who purchases this optional credit is already receiving a retirement annuity under this Article, the annuity shall be recalculated as if the annuitant had applied for the leave of absence credit at the time of retirement. The difference between the entitled annuity and the actual annuity shall be credited to the purchase of the optional credit. The remainder of the purchase cost of the optional credit shall be paid on or before April 1, 1992.
        The change in this paragraph made by Public Act
    
86-273 shall be applicable to teachers who retire after June 1, 1989, as well as to teachers who are in service on that date.
        (6) For a person who first becomes a member before
    
the effective date of this amendatory Act of the 98th General Assembly, any days of unused and uncompensated accumulated sick leave earned by a teacher. The service credit granted under this paragraph shall be the ratio of the number of unused and uncompensated accumulated sick leave days to 170 days, subject to a maximum of 2 years of service credit. Prior to the member's retirement, each former employer shall certify to the System the number of unused and uncompensated accumulated sick leave days credited to the member at the time of termination of service. The period of unused sick leave shall not be considered in determining the effective date of retirement. A member is not required to make contributions in order to obtain service credit for unused sick leave.
        Credit for sick leave shall, at retirement, be
    
granted by the System for any retiring regional or assistant regional superintendent of schools who first becomes a member before the effective date of this amendatory Act of the 98th General Assembly at the rate of 6 days per year of creditable service or portion thereof established while serving as such superintendent or assistant superintendent.
        (7) Periods prior to February 1, 1987 served as an
    
employee of the Illinois Mathematics and Science Academy for which credit has not been terminated under Section 15-113.9 of this Code.
        (8) Service as a substitute teacher for work
    
performed prior to July 1, 1990.
        (9) Service as a part-time teacher for work performed
    
prior to July 1, 1990.
        (10) Up to 2 years of employment with Southern
    
Illinois University - Carbondale from September 1, 1959 to August 31, 1961, or with Governors State University from September 1, 1972 to August 31, 1974, for which the teacher has no credit under Article 15. To receive credit under this item (10), a teacher must apply in writing to the Board and pay the required contributions before May 1, 1993 and have at least 12 years of service credit under this Article.
    (b-1) A member may establish optional credit for up to 2 years of service as a teacher or administrator employed by a private school recognized by the Illinois State Board of Education, provided that the teacher (i) was certified under the law governing the certification of teachers at the time the service was rendered, (ii) applies in writing on or after August 1, 2009 and on or before August 1, 2012, (iii) supplies satisfactory evidence of the employment, (iv) completes at least 10 years of contributing service as a teacher as defined in Section 16-106, and (v) pays the contribution required in subsection (d-5) of Section 16-128. The member may apply for credit under this subsection and pay the required contribution before completing the 10 years of contributing service required under item (iv), but the credit may not be used until the item (iv) contributing service requirement has been met.
    (c) The service credits specified in this Section shall be granted only if: (1) such service credits are not used for credit in any other statutory tax-supported public employee retirement system other than the federal Social Security program; and (2) the member makes the required contributions as specified in Section 16-128. Except as provided in subsection (b-1) of this Section, the service credit shall be effective as of the date the required contributions are completed.
    Any service credits granted under this Section shall terminate upon cessation of membership for any cause.
    Credit may not be granted under this Section covering any period for which an age retirement or disability retirement allowance has been paid.
(Source: P.A. 98-599, eff. 6-1-14.)
 
    (Text of Section WITHOUT the changes made by P.A. 98-599, which has been held unconstitutional)
    Sec. 16-127. Computation of creditable service.
    (a) Each member shall receive regular credit for all service as a teacher from the date membership begins, for which satisfactory evidence is supplied and all contributions have been paid.
    (b) The following periods of service shall earn optional credit and each member shall receive credit for all such service for which satisfactory evidence is supplied and all contributions have been paid as of the date specified:
        (1) Prior service as a teacher.
        (2) Service in a capacity essentially similar or
    
equivalent to that of a teacher, in the public common schools in school districts in this State not included within the provisions of this System, or of any other State, territory, dependency or possession of the United States, or in schools operated by or under the auspices of the United States, or under the auspices of any agency or department of any other State, and service during any period of professional speech correction or special education experience for a public agency within this State or any other State, territory, dependency or possession of the United States, and service prior to February 1, 1951 as a recreation worker for the Illinois Department of Public Safety, for a period not exceeding the lesser of 2/5 of the total creditable service of the member or 10 years. The maximum service of 10 years which is allowable under this paragraph shall be reduced by the service credit which is validated by other retirement systems under paragraph (i) of Section 15-113 and paragraph 1 of Section 17-133. Credit granted under this paragraph may not be used in determination of a retirement annuity or disability benefits unless the member has at least 5 years of creditable service earned subsequent to this employment with one or more of the following systems: Teachers' Retirement System of the State of Illinois, State Universities Retirement System, and the Public School Teachers' Pension and Retirement Fund of Chicago. Whenever such service credit exceeds the maximum allowed for all purposes of this Article, the first service rendered in point of time shall be considered. The changes to this subdivision (b)(2) made by Public Act 86-272 shall apply not only to persons who on or after its effective date (August 23, 1989) are in service as a teacher under the System, but also to persons whose status as such a teacher terminated prior to such effective date, whether or not such person is an annuitant on that date.
        (3) Any periods immediately following teaching
    
service, under this System or under Article 17, (or immediately following service prior to February 1, 1951 as a recreation worker for the Illinois Department of Public Safety) spent in active service with the military forces of the United States; periods spent in educational programs that prepare for return to teaching sponsored by the federal government following such active military service; if a teacher returns to teaching service within one calendar year after discharge or after the completion of the educational program, a further period, not exceeding one calendar year, between time spent in military service or in such educational programs and the return to employment as a teacher under this System; and a period of up to 2 years of active military service not immediately following employment as a teacher.
        The changes to this Section and Section 16-128
    
relating to military service made by P.A. 87-794 shall apply not only to persons who on or after its effective date are in service as a teacher under the System, but also to persons whose status as a teacher terminated prior to that date, whether or not the person is an annuitant on that date. In the case of an annuitant who applies for credit allowable under this Section for a period of military service that did not immediately follow employment, and who has made the required contributions for such credit, the annuity shall be recalculated to include the additional service credit, with the increase taking effect on the date the System received written notification of the annuitant's intent to purchase the credit, if payment of all the required contributions is made within 60 days of such notice, or else on the first annuity payment date following the date of payment of the required contributions. In calculating the automatic annual increase for an annuity that has been recalculated under this Section, the increase attributable to the additional service allowable under P.A. 87-794 shall be included in the calculation of automatic annual increases accruing after the effective date of the recalculation.
        Credit for military service shall be determined as
    
follows: if entry occurs during the months of July, August, or September and the member was a teacher at the end of the immediately preceding school term, credit shall be granted from July 1 of the year in which he or she entered service; if entry occurs during the school term and the teacher was in teaching service at the beginning of the school term, credit shall be granted from July 1 of such year. In all other cases where credit for military service is allowed, credit shall be granted from the date of entry into the service.
        The total period of military service for which credit
    
is granted shall not exceed 5 years for any member unless the service: (A) is validated before July 1, 1964, and (B) does not extend beyond July 1, 1963. Credit for military service shall be granted under this Section only if not more than 5 years of the military service for which credit is granted under this Section is used by the member to qualify for a military retirement allotment from any branch of the armed forces of the United States. The changes to this subdivision (b)(3) made by Public Act 86-272 shall apply not only to persons who on or after its effective date (August 23, 1989) are in service as a teacher under the System, but also to persons whose status as such a teacher terminated prior to such effective date, whether or not such person is an annuitant on that date.
        (4) Any periods served as a member of the General
    
Assembly.
        (5)(i) Any periods for which a teacher, as defined in
    
Section 16-106, is granted a leave of absence, provided he or she returns to teaching service creditable under this System or the State Universities Retirement System following the leave; (ii) periods during which a teacher is involuntarily laid off from teaching, provided he or she returns to teaching following the lay-off; (iii) periods prior to July 1, 1983 during which a teacher ceased covered employment due to pregnancy, provided that the teacher returned to teaching service creditable under this System or the State Universities Retirement System following the pregnancy and submits evidence satisfactory to the Board documenting that the employment ceased due to pregnancy; and (iv) periods prior to July 1, 1983 during which a teacher ceased covered employment for the purpose of adopting an infant under 3 years of age or caring for a newly adopted infant under 3 years of age, provided that the teacher returned to teaching service creditable under this System or the State Universities Retirement System following the adoption and submits evidence satisfactory to the Board documenting that the employment ceased for the purpose of adopting an infant under 3 years of age or caring for a newly adopted infant under 3 years of age. However, total credit under this paragraph (5) may not exceed 3 years.
        Any qualified member or annuitant may apply for
    
credit under item (iii) or (iv) of this paragraph (5) without regard to whether service was terminated before the effective date of this amendatory Act of 1997. In the case of an annuitant who establishes credit under item (iii) or (iv), the annuity shall be recalculated to include the additional service credit. The increase in annuity shall take effect on the date the System receives written notification of the annuitant's intent to purchase the credit, if the required evidence is submitted and the required contribution paid within 60 days of that notification, otherwise on the first annuity payment date following the System's receipt of the required evidence and contribution. The increase in an annuity recalculated under this provision shall be included in the calculation of automatic annual increases in the annuity accruing after the effective date of the recalculation.
        Optional credit may be purchased under this
    
subsection (b)(5) for periods during which a teacher has been granted a leave of absence pursuant to Section 24-13 of the School Code. A teacher whose service under this Article terminated prior to the effective date of P.A. 86-1488 shall be eligible to purchase such optional credit. If a teacher who purchases this optional credit is already receiving a retirement annuity under this Article, the annuity shall be recalculated as if the annuitant had applied for the leave of absence credit at the time of retirement. The difference between the entitled annuity and the actual annuity shall be credited to the purchase of the optional credit. The remainder of the purchase cost of the optional credit shall be paid on or before April 1, 1992.
        The change in this paragraph made by Public Act
    
86-273 shall be applicable to teachers who retire after June 1, 1989, as well as to teachers who are in service on that date.
        (6) Any days of unused and uncompensated accumulated
    
sick leave earned by a teacher. The service credit granted under this paragraph shall be the ratio of the number of unused and uncompensated accumulated sick leave days to 170 days, subject to a maximum of 2 years of service credit. Prior to the member's retirement, each former employer shall certify to the System the number of unused and uncompensated accumulated sick leave days credited to the member at the time of termination of service. The period of unused sick leave shall not be considered in determining the effective date of retirement. A member is not required to make contributions in order to obtain service credit for unused sick leave.
        Credit for sick leave shall, at retirement, be
    
granted by the System for any retiring regional or assistant regional superintendent of schools at the rate of 6 days per year of creditable service or portion thereof established while serving as such superintendent or assistant superintendent.
        (7) Periods prior to February 1, 1987 served as an
    
employee of the Illinois Mathematics and Science Academy for which credit has not been terminated under Section 15-113.9 of this Code.
        (8) Service as a substitute teacher for work
    
performed prior to July 1, 1990.
        (9) Service as a part-time teacher for work performed
    
prior to July 1, 1990.
        (10) Up to 2 years of employment with Southern
    
Illinois University - Carbondale from September 1, 1959 to August 31, 1961, or with Governors State University from September 1, 1972 to August 31, 1974, for which the teacher has no credit under Article 15. To receive credit under this item (10), a teacher must apply in writing to the Board and pay the required contributions before May 1, 1993 and have at least 12 years of service credit under this Article.
    (b-1) A member may establish optional credit for up to 2 years of service as a teacher or administrator employed by a private school recognized by the Illinois State Board of Education, provided that the teacher (i) was certified under the law governing the certification of teachers at the time the service was rendered, (ii) applies in writing on or after August 1, 2009 and on or before August 1, 2012, (iii) supplies satisfactory evidence of the employment, (iv) completes at least 10 years of contributing service as a teacher as defined in Section 16-106, and (v) pays the contribution required in subsection (d-5) of Section 16-128. The member may apply for credit under this subsection and pay the required contribution before completing the 10 years of contributing service required under item (iv), but the credit may not be used until the item (iv) contributing service requirement has been met.
    (c) The service credits specified in this Section shall be granted only if: (1) such service credits are not used for credit in any other statutory tax-supported public employee retirement system other than the federal Social Security program; and (2) the member makes the required contributions as specified in Section 16-128. Except as provided in subsection (b-1) of this Section, the service credit shall be effective as of the date the required contributions are completed.
    Any service credits granted under this Section shall terminate upon cessation of membership for any cause.
    Credit may not be granted under this Section covering any period for which an age retirement or disability retirement allowance has been paid.
(Source: P.A. 96-546, eff. 8-17-09.)