§ 4 — Creditable service

Section 4. (1)Qualifications for Credit for Service.-- (a) Any member in service shall, subject to the provisions and limitations of sections one to twenty-eight inclusive, be credited with all service rendered by him as an employee in any governmental unit after becoming a member of the system pertaining thereto; provided, that in no event shall he be credited with more than one year of creditable service for all such membership service rendered during any one calendar year.(b) Periods of service in any governmental unit prior to the date a system becomes operative therein rendered by any employee who becomes a member when such system first becomes operative in such governmental unit, or who becomes a member as otherwise provided for in paragraph (6) (f) of section three, shall, subject to the provisions and limitations of sections one to twenty-eight inclusive, be counted as creditable prior service; provided, that in no event shall any such person be credited with more than one year of creditable service for all such prior service rendered during any one calendar year.(c) Creditable service in the case of any member shall include any period of his continuous absence with full regular compensation, or in the event of his absence with partial regular compensation such period or portion thereof, if any, as the board shall determine. Creditable service in the case of any member may be allowed by the board for any period of his continuous absence without regular compensation which is not in excess of one month. Any portion of any leave or period of continuous absence of any member without regular compensation which is in excess of one month shall not be counted as creditable service except as specifically otherwise provided for in this section, but no duly authorized leave or period of absence shall be deemed to be a termination of membership or service.(d) Any person who became or becomes an employee by reason of the taking over by the commonwealth, or by the metropolitan district commission or by any district, of any institution, or of any public or quasi-public enterprise, controlled and operated by a political subdivision of the commonwealth or by a corporation, except such a person employed by the metropolitan district water supply commission who has not elected or does not elect to become a member of the state employees' retirement system, shall be credited with such service as would have been creditable service had it been rendered by him under the provisions of sections one to twenty-eight inclusive, or under corresponding provisions of earlier laws.(e) This section shall not apply to any employee who was eligible to and did not join a contributory retirement system established under the provisions of sections one to twenty-eight inclusive, or under corresponding provisions of earlier laws or of any special law, or to any such employee who was formerly a member of any such system, to the extent applicable to his service prior to his last becoming a member, unless and until he shall pay into the annuity savings fund of the system the makeup payments, if any, required by subdivision (3), (6) or (8), as the case may be, of section three.(f) Creditable service for periods of out-of-state service in the case of any member who has acquired the right to credit for such service as a member of the teachers' retirement system, or creditable service for periods of intra-state service in other governmental units where no system existed in the case of any employee who is a member of any system, shall be allowed as provided for in subdivision (4) or (5) respectively, of section three, or as provided for under corresponding provisions of earlier laws to the extent that such credit had been established prior to January first, nineteen hundred and forty-six.(f1/2) Creditable service for periods of nonpublic school service in the case of any member who has acquired the right to credit for such service as a member of the teachers' retirement system, shall be allowed as provided for in subdivision (4A) of section three; provided that such nonpublic school service was rendered prior to January first, nineteen hundred and seventy-three.(g) Any person who is a member of one or more systems and who has received or shall receive regular compensation paid jointly by two or more governmental units, shall, subject to the provisions of subdivision (7) of section three, while continuing in such joint employment, be allowed such creditable service as the board or boards may determine subject to the approval of the actuary; provided, that in no event shall any such person be credited with more than one year of creditable service for all such service rendered during any one calendar year.(g1/2) The period or periods before 1975 during which any member in service of the teachers' retirement system or any teacher who is a member of the Boston retirement system resigned for the purposes of maternity leave or was on unpaid leave of absence for such purposes from the governmental unit in which the member was employed as a teacher and had established membership in a Massachusetts contributory retirement system shall be allowed as creditable service, on a proportionate basis which the board shall determine according to rules and regulations adopted by the board and approved by the commission; provided, that no credit shall be allowed unless such member has paid into the Annuity Savings Fund of the system by December 31, 2001, in one sum or in installments, upon such terms and conditions as the board may prescribe, an amount equal to the deductions that would have been withheld had the member continued in service, as determined by the board, together with buyback interest. No credit shall be allowed and no payment shall be accepted under this paragraph until such member shall have completed ten or more years of membership service, but if any such member completes ten years of service after December 31, 2001, the member shall be permitted to make payment under this paragraph within 18 months of the date she has completed ten years of service. The maximum creditable service allowable under this paragraph for any member shall not exceed four years.(g3/4) The period or periods before 1975 during which any retired member of the Teachers Retirement System or any member who retired as a teacher from the Boston retirement system who (i) is living and retired before September 1, 2000, (ii) resigned for the purposes of maternity leave or was on unpaid leave of absence for such purposes from the governmental unit in which the member was employed as a teacher, and (iii) had established membership in a Massachusetts contributory retirement system shall be allowed under this paragraph a maximum of creditable service not to exceed 4 years creditable service. No credit shall be allowed under this paragraph for any member who was not retired as of September 1, 2000. The credit allowed under this paragraph shall increase the retirement allowance payments beginning on April 2, 2012.(h) The period or periods during which any member who is a veteran as defined in section one was on leave of absence from the governmental unit to which the system of which he is a member pertains, for the purpose of serving in such campaign and until he was discharged or released from such service in the armed forces, shall be allowed as creditable service.Any such period of leave of absence which is subsequent to his becoming a member of such system shall be counted as membership service, and any such period prior thereto shall be counted as prior service; provided, that he would have been entitled to such credit in the event he had continued in the active service of such governmental unit during the period of time covered by such leave of absence.Any member who served in the armed forces between January first, nineteen hundred and forty and the termination of the Selective Service Act of 1948, shall have such actual service credited to him as creditable service when reinstated or reemployed in his former position or in a similar position or when employed in any governmental unit in a position which is subject to the provisions of sections one to twenty-eight, inclusive, within two years of his discharge or release from such service; provided, however, that such service shall not be construed to include service for more than four years unless such further period of service in excess of four years was involuntary service required by the government of the United States or unless such service in excess of four years was rendered prior to July first, nineteen hundred and sixty-four and such member was reinstated or reemployed on or before June thirtieth, nineteen hundred and sixty-six. The provisions of sections nine and nine A of chapter seven hundred and eight of the acts of nineteen hundred and forty-one, as amended, and as may be further amended, shall be applicable to any person referred to in section one of said chapter seven hundred and eight who is a member of any retirement system established under the provisions of this chapter whose last discharge or release from military service was under honorable conditions as defined in defense department regulations.[ Fourth paragraph of paragraph (h) of subdivision (1) effective until August 8, 2024. For text effective August 8, 2024, see below.]Notwithstanding the provisions of this chapter or any other general or special law, rule or regulation to the contrary, a member in service of a retirement system as defined in section one who is a veteran who served in the armed forces of the United States shall be entitled to credit for active service in the armed services of the United States; provided, however, that such active service shall not be credited until such member has paid into the annuity savings fund of such system, in one sum or in installments, upon such terms and conditions as the board may prescribe, makeup payments, for each year of creditable service sought, of an amount equal to the ten percent of the regular annual compensation of the member when said member entered the retirement system; and, provided further that such creditable service shall not be construed to include service for more than four years provided further, that such creditable service shall not be allowed for any period of active service for which said veteran has received credit pursuant to paragraph (h) of subsection (1) of section 4 of chapter thirty-two of the General Laws. This act shall apply to National Guard and Active Reserve personnel, both former and present. Creditable service time, both enlisted and commissioned may be applied toward retirement on a ratio of five years guard service or five years active reserve service substitutable for each year of active service.[ Fourth paragraph of paragraph (h) of subdivision (1) as amended by 2024, 178, Sec. 18 effective August 8, 2024. For text effective until August 8, 2024, see above.]Notwithstanding the provisions of this chapter or any other general or special law, rule or regulation to the contrary, a member in service of a retirement system as defined in section 1 shall be provided written notice by the retirement board upon entry into service that if they qualify as a veteran who served in the armed forces of the United States, they shall be entitled to credit for active service in the armed services of the United States; provided, however, that such active service shall not be credited until such member, prior to or within 1 year of vesting pursuant to this chapter, has paid into the annuity savings fund of such system, in 1 sum or in installments, upon such terms and conditions as the board may prescribe, makeup payments, for each year of creditable service sought, of an amount equal to 10 per cent of the regular annual compensation of the member when said member entered the retirement system; provided further, that such creditable service shall not be construed to include service for more than 4 years; and provided further, that such creditable service shall not be allowed for any period of active service for which said veteran has received credit pursuant to this paragraph. This paragraph shall apply to national guard and active reserve personnel, both former and present. Creditable service time, both enlisted and commissioned, may be applied toward retirement on a ratio of 5 years of national guard service or 5 years of active reserve service substitutable for each year of active service. National guard and active reserve personnel shall not be precluded from making said purchase if they qualify as a veteran after vesting or if they reach the maximum of 4 years of eligible service purchase after vesting and qualifying as a veteran; provided, however, that they enter into a purchase agreement within 5 years of the last occurring event.(h1/2) Any member in service of the teachers' retirement system or teacher who is a member of the Boston retirement system, and who is or was employed as a teacher as defined by section 1 in a vocational-technical school or in a public school's vocational-technical program approved by the department of education under chapter 74 may receive creditable service for any period or periods of prior work experience in the occupational field in which the member became a vocational-technical teacher and which was required as a condition of the member's employment and licensure under regulations of the department of education. No credit shall be allowed until the member has paid into the Annuity Savings Fund of the system before any retirement allowance becomes effective for the member, in 1 sum, or in installments, upon the terms and conditions that the board prescribes, makeup payments of an amount equal to 10 per cent of the regular annual compensation of the member as of the member's most recent date of entry into membership in the teachers' retirement system or as a teacher in the Boston retirement system, for each year of service purchased plus buyback interest thereon. No credit shall be allowed and no payment shall be accepted under this paragraph until the member has completed 10 or more years of membership service. The creditable service allowable under this paragraph for any member shall not exceed 3 years. Members in service of a retirement system who make application for this creditable service shall be notified by the retirement board of their eligibility for such creditable service, and, if they are eligible, shall also be notified by the retirement board that they have the following options: (1) to purchase the service in a lump sum within 180 days of the notice, or (2) to enter into an installment agreement within 180 days of the notice to pay for the service.(i) Any member who is an employee of the division of banks and loan agencies and who is assigned by the commissioner of banks to serve in the liquidation of any banking corporation under the supervision of said commissioner and who receives compensation for such service from the funds of such corporation, shall deposit in the annuity savings fund of the state retirement system such amounts as he would have contributed during the period of such service, but in no event for more than three years, had he remained on the payroll of the commonwealth. In such case he shall receive full credit for such service as if his salary had been paid by the commonwealth.(j) Credit shall be allowed for any additional contribution made by an employee for the period between July first, nineteen hundred and thirty-seven, and January first, nineteen hundred and forty-six, for salary in excess of the limit or limits allowed in the retirement system during that period.(k) Any member whose services have been requested of the governor by the United States Department of State and who was granted a leave of absence to perform such services shall receive full credit for retirement purposes, for the period of such service, provided that he pays into the annuity savings fund of the state employees' retirement system the amount that would have been withheld as regular deductions from his salary had he not been granted such leave.(l) Any member of a retirement system who most recently became a member prior to January first, nineteen hundred and eighty-eight, and who is engaged in a teaching position and who previously served in a position in the state department of education under the control of the commissioner of education, but who was paid directly by the federal government from federal funds, may establish such service as creditable service by depositing in the annuity savings fund of the system of which he is a member an amount equal to five per cent of the compensation received during such period of service, plus buyback interest to the date of such deposit.(l1/2) Any member of a retirement system who most recently became a member on or after January first, nineteen hundred and eighty-eight, and is engaged in a teaching position and who has previously served in a position in the state department of education under the control of the commissioner of education but who was paid directly by the federal government from federal funds, may establish such service as creditable service by depositing in the annuity savings fund of the system of which he is a member the amount which would have been withheld as regular deductions from his salary for such service, plus buyback interest to the date of such deposit.(l3/4) A member of the state retirement system who is eligible to receive a retirement benefit pursuant to this chapter who served as an employee of an educational collaborative prior to 1983 may establish such service as creditable service by depositing in the annuity savings fund of the state retirement system in 1 sum or in installments, upon such terms and conditions as the board may prescribe, an amount equal to 10 per cent of the compensation received by the member during such period plus buyback interest to the date of the deposit.(m) Any employee who was a member in service at the time of sustaining an injury or undergoing a hazard on account of which he received weekly payments for total incapacity under the provisions of sections sixty-nine to seventy-five, inclusive, of chapter one hundred and fifty-two, or a lump sum settlement payable under section forty-eight of said chapter one hundred and fifty-two shall have credited to him as creditable service under the system any period prior to June first, nineteen hundred and fifty-one during which he received such weekly payments, or any such period prior to said date represented by the allocation of any lump sum settlement payable to him in lieu of such weekly payments; provided, that such employee returned to his former position, or a similar position, upon the termination of the leave caused by such injury or hazard.(n) Any member of a retirement system who most recently became a member prior to January first, nineteen hundred and eighty-eight and who previously served in a position with the Veterans Employment Service of the United States Employment Service and who, during such service, was attached to and served at offices of the division of employment and training, but who was paid directly by the Federal Government from federal funds, may establish such services as creditable service by depositing in the annuity savings fund of the system of which he is a member an amount equal to five per cent of the compensation received by him during such period of service, plus buyback interest to the date of such deposit.(n1/2) Any member of a retirement system who first became a member on or after January first, nineteen hundred and eighty-eight, and who previously served in a position with the Veterans Employment Service of the United States Employment Service and who, during such service, was attached to and served at offices of the division of employment and training, but who was paid directly by the Federal Government from federal funds, may establish such service as creditable service by depositing in the annuity savings fund of the system of which he is a member the amount which would have been withheld as regular deductions from his salary for such service, plus buyback interest to the date of such deposit.(o) The service of a state, county or municipal employee employed or elected in a position receiving compensation of less than $5,000 annually, which service occurs on or after July 1, 2009, shall not constitute creditable service for purposes of this chapter.(p) Any member of a contributory retirement system who is engaged in a teaching position and holds a certificate issued by the department of education or is exempted from the requirement of certification and who was previously engaged in teaching pupils in any non-public school in the commonwealth, if the tuition of all such pupils taught was financed in part or in full by the commonwealth may, before the date any retirement allowance becomes effective for him, establish such service as creditable service by depositing into the annuity savings fund of the system of which he is a member in one sum, or in installments, upon such terms and conditions as the board may prescribe, an amount equal to five per cent of the compensation received by him during such period of service plus buyback interest to the date of such deposit for such previous period, or most recent portion thereof, as he may elect. Payment shall not be made and no credit shall be allowed for such non-public school service in excess of the total service rendered in a public school of the commonwealth to which the member would be entitled to receive credit if he remained in service to age sixty-five, with the maximum credit for service in such non-public schools not to exceed ten years; provided, that no credit shall be allowed and no payment shall be accepted for any service for which the member shall be entitled to receive a retirement allowance, annuity or pension from any other source. Upon completion of such payments, such member shall receive the same credit for such period of his previous non-public school service or portion thereof elected, as would have been allowed had such service been rendered by him in a public school of the commonwealth. Such member shall furnish the board with such information as it shall require to determine the amount to be paid and the credit to be allowed under this paragraph. At the time a retirement allowance becomes due to a member or to a beneficiary under option (d) of subdivision (2) of section twelve, if the service rendered in public schools of the commonwealth on the date either the retirement allowance becomes effective, or on the date the member attained age sixty-five, whichever occurs first, is less than the service in said non-public schools for which the member has paid, credit shall be allowed only for the most recent service rendered in said non-public schools equal to such service rendered in the public schools of the commonwealth and the amount paid for such additional service shall be refunded with accumulated interest, refund to be made only when the retirement allowance becomes due to the member or to the beneficiary under option (d) of subdivision (2) of section twelve, and if it is found that payment has been accepted for any service for which the member is entitled to a retirement allowance, annuity or pension from any other source, the amount paid for such service with accumulated interest shall also be refunded with no retirement credit allowed.(q) Any veteran employed in the service of the commonwealth or of any county, city, town or district, or any housing authority or any redevelopment authority thereof, who is a member in service in a public retirement system, and who is elected to the office of national commander of any congressionally chartered veterans organization, shall, while on leave of absence for the purpose of acting in a full-time capacity in said office, be considered on leave of absence without pay for the period of his term of office as national commander; provided, however, that such leave of absence shall not exceed fifteen months; and, provided further, that the period of time of such leave of absence shall be deemed creditable service for retirement purposes upon said member's depositing into the retirement fund of the system of which he is a member the total amount of the payments said member would have paid into the system had he remained in the service during said leave of absence, in one lump sum, or in installments, upon such terms as the board of retirement may prescribe. The provisions of this paragraph shall be effective for the members of the state employees' retirement system and of the teachers' retirement system and for the members of a county retirement system by vote of the county retirement board, subject to the approval of the county commissioners, of a town retirement system by vote of the town retirement board, subject to the approval of the town meeting, of a city retirement system by vote of the city retirement board subject to the approval of the council, and of a district retirement system by vote of the district retirement board, subject to the approval of the district meeting.An active or inactive member of a contributory system who was a member of the judiciary and resigned from office without meeting the requirements for retirement or resignation as set forth in the third or fourth paragraphs of said section sixty-five A may not establish such judicial service as creditable service for retirement purposes except by depositing into the annuity saving fund of the system of which he is a member in one sum, or in installments, upon such terms and conditions as the board may prescribe, an amount equal to seven per cent of the compensation received by him during such period of judicial service plus regular interest to the date of such deposit for such previous period, or most recent portion thereof, as he may elect. Payment shall not be made and no credit shall be allowed for any such judicial service for which the member shall be entitled to receive a retirement allowance, annuity or pension from any other source. Upon completion of such payments, such member shall receive the same credit for such period of his previous judicial service or portion thereof elected as would have been allowed had such service been rendered by him while an active member of such system.(r) Notwithstanding any general or special law to the contrary, a member in service or member inactive, as defined in section 3, of a retirement system, who served as a volunteer to the Peace Corps, who completes 10 or more years of membership service as a public school teacher or public school guidance counselor, and who retires on or after September 1, 2002, shall receive full credit for the period of such volunteer service but not more than 3 years. Eligibility for the creditable service of members in service of a retirement system shall be conditioned upon payment, in 1 sum or in installments upon such terms as the applicable retirement board may provide, into the annuity savings fund of the applicable retirement system, of an amount equal to the contributions such member in service would have otherwise paid into the retirement system plus buyback interest thereon for the period of volunteer service based upon the annual salary the member received in the first year of membership service after that volunteer service.(r1/2) Notwithstanding any general or special law to the contrary, a member in service who: (i) served in the United States Public Health Service Commissioned Corps or the National Oceanic and Atmospheric Administration Commissioned Officer Corps; (ii) has completed not less than 4 years of membership service; and (iii) has retired or will retire on or after January 1, 1975 shall receive full credit for the period of such service; provided, however, that such a member shall receive credit for not more than 4 years of that service. Eligibility for the creditable service of members in service shall be conditioned upon payment into the annuity savings fund of the applicable retirement system, in 1 sum or in installments upon such terms as the applicable retirement board may provide, of an amount equal to the contributions that a member would have otherwise paid into the retirement system plus buyback interest thereon for the period of commissioned corps service based upon the annual salary the member received in the first year of membership service after the member's commissioned corps service.(s) Any member in service of the state employees' retirement system who, immediately preceding the establishment of membership in that system or re-entry into active service in that system, was compensated for service to the commonwealth as a contract employee for any department, agency, board or commission of the commonwealth may establish as creditable service up to 4 years of that service if the member has 10 years of creditable service with the state employees' retirement system, and if the job description of the member in the position which the member holds upon entry into service or re-entry into active service is substantially similar to the job description of the position for which the member was compensated as a contract employee. No credit shall be allowed until the member has paid into the Annuity Savings Fund of the state employees' retirement system before any retirement allowance becomes effective for the member, in a lump sum or in installments, upon the terms and conditions that the state board of retirement prescribes, makeup payments of an amount equal to that which would have been withheld as regular deductions for the service as a contract employee if the service had been rendered as a state employee and the member had been a member of the state employees' retirement system during the period the service was rendered, plus buyback interest on that amount. Eligible members who worked part-time as contract employees shall be eligible for creditable service proportionately equal to their part-time service.Upon completion of the payments, the member shall receive the same credit for the period of previous service as a contract employee as would have been allowed if the service had been rendered by the member as a state employee. Members in service of the state retirement system who make application for this creditable service shall, subject to the rules and regulations of the state board of retirement, be notified by the state board of retirement of their eligibility for creditable service and, if they are eligible, shall also be notified by the state board of retirement that they have the following options: (1) to purchase the service in a lump sum within 180 days after the date of the notice; or (2) to enter into an installment agreement within 180 days after the date of the notice to pay for the service. No creditable service shall be allowed under this section unless the member provides documentation of the member's service as a contract employee satisfying the state board of retirement's requirements.(2)Filing and Verification of Statements of Service. -- (a) Each person becoming a member of the system shall, within one year thereafter and under such rules and regulations adopted by the board and approved by the public employee retirement administration commission, file a detailed statement of all service for which he claims credit rendered by him as an employee of any governmental unit prior to the date as of which such system became operative herein including in such statement such facts as the board may require. Each such person shall also so file a detailed statement of any other service rendered by him as an employee prior to the date of his becoming a member for which he may claim credit as provided for in subdivisions (3) to (8) inclusive, of section three, or in paragraph (c) of this subdivision.(b) The board, subject to rules and regulations promulgated by the commission, shall fix and determine how much service in any calendar year is equivalent to a year of service. In all cases involving part-time, provisional, temporary, temporary provisional, seasonal or intermittent employment or service of any employee in any governmental unit, including such employment or service of any state official or of any person elected by popular vote to a county or municipal office or position, the board, under appropriate rules and regulations which shall be subject to the approval of the actuary, shall fix and determine the amount of creditable prior service, if any, and the amount of credit for membership service of any such employee who becomes a member, including any prescribed waiting period before eligibility for membership, established either by law or board ruling, prior to January first, nineteen hundred and forty-six, for which such service credit was given upon attaining membership; provided, that in the case of any such employee whose work is found by the board to be seasonal in its nature, the board shall credit as the equivalent of one year of service, actual full-time service of not less than seven months during any one calendar year; and provided, further, that the board shall credit as full-time service not to exceed a maximum of five years that period of time during which a reserve or permanent-intermittent police officer or a reserve, permanent-intermittent or call fire fighter was on his respective list and was eligible for assignment to duty subsequent to his appointment; and provided, further, that such service as a permanent-intermittent or call fire fighter shall be credited only if such permanent-intermittent or call fire fighter was later appointed as a permanent member of the fire department. For a reserve or permanent-intermittent police officer or a reserve, permanent-intermittent or call fire fighter retiring from a governmental unit accepting the provisions of this sentence, the board shall credit, in addition to the five years of credit allowed pursuant to the preceding sentence, as one day of full-time service each day in any year which is subsequent to the fifth year following said appointment and on which a reserve or permanent-intermittent police officer or a reserve, permanent-intermittent or call fire fighter was assigned to and actually performed duty as a reserve or permanent-intermittent police officer or reserve, permanent-intermittent or call fire fighter; provided, however, that such service as a permanent-intermittent or call fire fighter shall be credited only if such fire fighter was later appointed as a permanent member of the fire department; provided, further, that this sentence shall take effect in a city by vote of the city council in accordance with its charter, in a town which maintains a separate contributory retirement system by vote of the town meeting, in a town whose eligible employees are members of the county retirement system of the county wherein such town lies by vote of a town meeting and by acceptance by the county commissioners of said county, in a district which maintains a separate contributory retirement system by vote of the district meeting, and in a district the eligible employees of which are members of a county retirement system by vote of the district meeting and by acceptance of the county commissioners of said county.(b1/2) In any city, town, or fire district, which accepts the provisions of this paragraph, service as a permanent-intermittent or call firefighter shall be credited as full-time service as provided in paragraph (b), except that credit for such service shall not be conditioned upon the appointment of said permanent-intermittent or call firefighter as a permanent member of the fire department. This paragraph shall take effect in a city by vote of the city council in accordance with its city charter, in a town which maintains a separate contributory retirement system by vote of the town meeting, in a town whose eligible members are members of the county retirement system of the county wherein such town lies by vote of the town meeting, in a district which maintains a separate contributory retirement system by vote of the district meeting, and in a district the eligible employees of which are members of a county retirement system by vote of the district meeting.(c) In the case of any employee of any governmental unit who is a member of the retirement system pertaining thereto, the board may allow credit, upon whatever proportionate basis it shall determine under appropriate rules and regulations which shall be subject to the approval of the actuary, for any previous period of part-time, provisional, temporary, temporary provisional, seasonal or intermittent employment or service rendered by him after such a retirement system becomes operative and while he was not eligible for membership excluding any prescribed waiting period under the provisions of the law or under the board's rules and regulations in effect during such previous period before eligibility for membership, established either by law or board ruling in effect prior to January first, nineteen hundred and forty-six, for which such service credit was given upon attaining membership; provided, that after becoming a member or being reinstated as such, and before the date any retirement allowance becomes effective for him, he pays into the annuity savings fund of the system in one sum, or in installments, upon such terms and conditions as the board may prescribe, make-up payments of an amount equal to that which would have been withheld as regular deductions from his regular compensation had he been eligible for membership and been a member of such system during such previous period, together with buyback interest. In the event any retirement allowance becomes effective for him before the completion of such make-up payments, such member shall, in addition to credit for his actual membership service, be entitled to credit for that proportion of his service rendered prior to the date of his becoming a member which the total amount of his make-up payments actually made, together with regular interest thereon to the date his retirement allowance becomes effective, bears to the total amount of what his make-up payments, together with regular interest thereon to such latter date, would have been had he made payment thereof in one sum on such latter date.(d) The board shall verify as soon as practicable after the filing of any such statement of service, the service therein claimed, and shall certify as creditable service all or such part of the service claimed as may be allowable under such rules and regulations as the board may adopt subject to the approval of the actuary.(3)Prior Service Certificates.-- (a) The board, upon its verification of any statement of service of any member entitled to credit for prior service, shall issue to him a prior service certificate certifying the length of service rendered by him prior to the date the system became operative with which he is credited by the board. Such prior service certificate shall, for retirement purposes, be final and conclusive as to such service as long as his membership continues; provided, that any member may within one year from the date of issue or modification of such certificate request the board in writing to modify or correct his prior service certificate. The board shall issue said prior service certificate within six months of the filing of a statement of service of any member.(b) The prior service certificate of any member shall become void upon the cessation of his membership or shall become void upon the termination of his service otherwise than by retirement unless he remains a member inactive and unless as such he is eligible to receive a retirement allowance under the provisions of section ten. If his membership is restored or reinstated as provided for in subdivision (6) of section three, or is transferred or reestablished as provided for in subdivision (8) of such section, he shall again be entitled to such prior service credit or to that proportion thereof which he restores to the extent that he pays into the annuity savings fund of the system the make-up payments, if any, required by such subdivisions. Upon the completion of any such make-up payments, or if none are required then upon his again becoming a member in service as provided for in said subdivisions, his prior service certificate shall be fully reinstated.(4)Membership and Retirement Certificates.-- The board shall issue to each person upon his becoming a member of any system a certificate of membership therein which shall remain in effect as long as such membership continues. The board, subject to the approval of the commission, shall issue to each member upon his retirement, or when a retirement allowance becomes effective for him under the provisions of section ten, a retirement certificate which shall be evidence of his right to a retirement allowance and shall state the amount thereof. Under this section, the board, with the approval of the commission, shall adopt rules and regulations to provide that such member shall on an annual basis file an affidavit under the penalties of perjury, certifying such information as the board deems appropriate. Any certificate issued under this subdivision or under subdivision (3) of this section shall be on a prescribed form.