Section 28. (1) Acceptance by Towns. — At the state election in nineteen hundred and forty-six and at each state election thereafter, sections one to twenty-eight inclusive shall be submitted for acceptance to the registered voters of each town which has not accepted for all of its employees except teachers the applicable provisions of such sections or corresponding provisions of earlier laws. Submission for acceptance by any such town shall be in the form of the following question which shall be printed upon the official ballot to be used at such state election—''Shall sections one to twenty-eight inclusive of chapter thirty-two of the General Laws, authorizing any city or town to establish a contributory retirement system for its employees, be accepted by this town as applicable to all of its employees except teachers who are eligible for membership in the teachers' retirement system?'' If a majority of the voters voting on the question at such state election in such town shall vote in the affirmative, said sections shall take effect in such town as provided for in subdivision (3) of this section.

(2) Acceptance by Cities or Towns having a Contributory Retirement System Established under a Special Act. — (a) Sections one to twenty-eight, inclusive, may be accepted in any city or town which has established a contributory retirement system for its employees under the provisions of a special law but which has not accepted for such employees the applicable provisions of such sections or corresponding provisions of earlier laws; in a city by vote of the city council, approved by the mayor, and in a town by vote of the selectmen.

(b) In case sections one to twenty-eight inclusive are accepted in any city or town as provided for in paragraph (a) of this subdivision, the retirement board of the previously established retirement system shall continue in office, with the same powers and duties as formerly, until the board established under such sections commences to function thereunder. If any members of the previously existing retirement system shall not elect to become members of the system established under the provisions of such sections, or if there are any retired members or beneficiaries under such previously existing retirement system, the latter board thereafter shall continue to operate such previously existing retirement system in accordance with the provisions of the special law relative thereto in addition to operating the system established under the provisions of such sections, and the retirement board of such previously existing system shall cease to exist. The board established under the provisions of such sections may, subject to the written approval of the public employee retirement administration commission, merge similar funds under both systems in accordance with such regulations pertaining thereto as the commission may promulgate.

(c) The provisions of paragraph (2)(b) of section three shall be applicable to all employees, except teachers who are eligible for membership in the teachers' retirement system, of any city or town which accepts sections one to twenty-eight inclusive as provided for in paragraph (a) of this subdivision, whether or not they are members of the previously existing retirement system. If any such employee who is a member of such previously existing retirement system elects not to become a member of the system established under the provisions of sections one to twenty-eight inclusive, he shall continue as a member of such previously existing retirement system. No employee shall become a member of the previously existing retirement system on or after the date the system established under the provisions of sections one to twenty-eight inclusive becomes operative in such city or town.

(d) Any employee of any such city or town who, having had the right to become a member of such previously existing retirement system failed to become or elected not to become such a member, may become a member of the system established under the provisions of sections one to twenty-eight inclusive, either by becoming a member as provided for in paragraph (c) of this subdivision or by becoming a member thereafter as provided for in clause (ii) of paragraph (2)(a) of section three; provided, that no such employee shall be entitled to credit for service rendered prior to the date of his becoming a member unless he shall pay into the annuity savings fund of such latter system the make-up payments provided for in subdivision (3) of section three, including therein make-up payments on account of the regular deductions which would have been withheld from his compensation had he joined such previously existing retirement system at his earliest opportunity.

(e) If any member of any such previously existing retirement system elects to become a member of the system established under the provisions of sections one to twenty-eight inclusive, amounts equal to his shares of all funds of such previously existing retirement system, as determined by the actuary, shall be transferred to the corresponding funds of the system established under the provisions of such sections.

(f) Any employee of a city or town who was specifically excluded from membership under the previously existing system, and who holds a position which would entitle him to membership under sections one to twenty-eight, inclusive, shall be entitled to prior service credit for service rendered prior to the acceptance of said sections.

(g) The words ''employee'' and ''employees'', as appearing in sections one to twenty-eight, inclusive, so far as said words apply expressly or by implication to employees of the city of Boston, shall include teachers and the employees of the county of Suffolk.

(h) In the case of any such city or town, any provision of any such special law requiring that the appropriation for the accumulated liability contribution to the pension fund shall be three per cent greater in amount each year is hereby repealed, and the amount to be appropriated for such purpose shall be such sum as is approved by the public employee retirement administration commission in each year.

(3) Establishment of System in a City or Town. — (a) The town clerk of any town which accepts sections one to twenty-eight, inclusive, by vote at any state election, as provided for in subdivision (1) of this section, shall file in the office of the public employee retirement administration commission within thirty days after such vote a certificate thereof sworn to by the election commissioners or other officers corresponding thereto. The city or town clerk of any city or town which accepts said sections one to twenty-eight, inclusive, by vote of the city council, approved by the mayor, or of the selectmen, as the case may be, as provided for in subdivision (2) of this section, shall forthwith file in the office of said commission a certificate of such vote certified by the city or town clerk.

Said commission shall, within fifteen days after such filing, issue to the mayor or selectmen a certificate to the effect that the retirement system established by said sections shall become operative in such city or town on the first day of January or of July or of October, whichever occurs first, following the expiration of three months after the date of such certificate.

(b) When any town having a population less than ten thousand accepts sections one to twenty-eight inclusive, the eligible employees of such town shall become members of the county retirement system of the county wherein such town lies, in lieu of the establishment of a system within and for such town. Such employees shall have all rights and obligations in such county retirement system in the same manner as if such a system were established in such town.

(c) If the town of Nantucket accepts sections one to twenty-eight inclusive, the eligible employees of such town, the eligible employees of the county of Nantucket and the eligible employees of any district located in such county, shall, subject to the provisions of such sections, become members of the county of Barnstable retirement system in lieu of the establishment of a system within and for such town or within and for the county of Nantucket. Such employees who become members shall have all rights and obligations in the county of Barnstable retirement system in the same manner as if such system were established in the county of Nantucket. The provisions of paragraph (7)(c) of section twenty-two shall apply so far as may be necessary to enable the county of Barnstable retirement system to recover from the county or town of Nantucket, or from any district in the county of Nantucket, as the case may be, its or their portion of the cost of operation and the expenses of administration of such system. Items of appropriation providing for any amounts allocated to any such political subdivision shall be included in the appropriations for each fiscal year for such political subdivision.

(4) Acceptance by Districts. — (a) Any district, all or part of which lies within the territory of any city or town which maintains or has adopted a contributory retirement system for its employees under the applicable provisions of sections one to twenty-eight inclusive, or any district which is located in two or more cities or towns, at least one of which has accepted the applicable provisions of such sections or corresponding provisions of earlier laws, or any district the cities and towns of which are located in more than one county, may provide retirement benefits for its employees if such district by a vote duly recorded shall accept sections one to twenty-eight inclusive, as far as applicable, except that in a veterans' services district the vote only of the district board shall be required to accept said provisions. A duly attested copy of such vote shall be filed by the clerk of the district, or other person performing like duties, in the office of the commission within thirty days after such vote. The public employee retirement administration commission shall, within fifteen days after the receipt of such attested copy, issue a certificate to be sent to such clerk or person in such district, to the effect that such sections shall become operative for the employees of such district on the first day of January or on the first day of July, whichever first occurs, next following the expiration of three months after the date of such certificate. The commission shall also notify the county commissioners, the mayor or the board of selectmen, and the retirement board of such county, city or town or the state board of retirement, as the case may be, within which such district lies, of the acceptance of such sections by the district and of the date as of which such sections shall become operative for its employees, except that in a mosquito control project or district the vote only of the district board of commissioners shall be required to accept said provisions; and except, that in the county cooperative extension service of the county of Suffolk the vote only of the trustees shall be required to accept said provisions. Any employee who becomes a member of a retirement system by the acceptance by a mosquito control project or district of this paragraph or by the acceptance by the county cooperative extension service of the county of Suffolk of this paragraph shall be credited with prior service in accordance with the provisions of sections one to twenty-eight, inclusive.

(b) On and after the date when sections one to twenty-eight inclusive become operative for the employees of any district as set forth in paragraph (a) of this subdivision, the eligible employees of such district shall become members of the system of the city or town within whose territory the district lies, or of the system of the largest of such cities or towns which maintains a system if the district lies within more than one city or town, or of the county system if the employees of such town have become members of such county system under the provisions of paragraph (b) of subdivision (3) of this section, in the same manner as if such a system were established in such district.

(c) Each district, the employees of which have become members of the state employees retirement system under the provisions of this subdivision, shall annually reimburse the state board of retirement for its pro rata share of any retirement allowance or pension paid by said board during the preceding calendar year which is based in whole or in part on service with such district. Notwithstanding any provisions of this paragraph to the contrary, educational collaboratives, as authorized by the provisions of section four E of chapter forty, shall annually reimburse the state board of retirement for the employer's normal cost as determined by the actuary, of benefits earned during each year by such collaborative employees who are members of the state employees' retirement systems. The actuary shall determine such cost as a percentage of the payroll of the collaborative for such employees based upon the most recent actuarial valuation of the state retirement system. Said reimbursed amount shall be deposited in the pension reserve fund of the state employees' retirement system.

(5) Acceptance by Housing Authorities. — (a) Any housing authority established under the provisions of section five of chapter one hundred and twenty-one B, and any redevelopment authority established under the provisions of section four of said chapter, may provide retirement benefits for its employees if such authority by a vote duly recorded shall accept sections one to twenty-eight, inclusive, as far as applicable. A duly attested copy of such vote shall be filed by the clerk of the authority, or other person performing like duties, in the office of the public employee retirement administration commission within thirty days after such vote. The public employee retirement administration commission shall, within fifteen days after the receipt of such attested copy, issue a certificate to be sent to such clerk or person in such authority, to the effect that such sections shall become operative for the employees of such authority on the first day of January or on the first day of July, whichever first occurs, next following the expiration of three months after the date of such certificate; provided, however, that in the case of a redevelopment authority established in a city or town having a housing authority which has accepted the provisions of sections one to twenty-eight, inclusive, said certificate shall be to the effect that such sections shall become operative for the employees of such redevelopment authority upon the receipt of such certificate. The commission shall also notify the county commissioners, the mayor or the board of selectmen, and the retirement board of such county, city or town, as the case may be, within which such authority lies, of the acceptance of such sections by the authority and of the date as of which such sections will become operative for its employees.

(b) On and after the date when sections one to twenty-eight, inclusive, become operative for the employees of any authority as set forth in paragraph (a) of this subdivision, the eligible employees of such authority shall become members of the system of the city or town within whose territory the authority lies, or of the county system if the employees of such town have become members of such county system under the provisions of paragraph (b) of subdivision (3) of this section, in the same manner as if such a system were established for such authority.

(c) The provisions of section fourteen of this chapter and of section seventy-three of chapter one hundred and fifty-two shall apply as if compensation payable under said chapter one hundred and fifty-two by such housing or redevelopment authority or its insurer were payable under sections sixty-nine to seventy-nine, inclusive, of said chapter.

(6) Acceptance by the Massachusetts Department of Transportation. — (a) The Massachusetts Department of Transportation may provide retirement benefits for its employees if said authority by a vote duly recorded shall accept sections one to twenty-eight, inclusive, as far as applicable. A duly attested copy of such vote shall be filed by the secretary-treasurer of the authority in the office of the public employee retirement administration commission within thirty days after such vote. The public employee retirement administration commission shall, within fifteen days after the receipt of such attested copy, issue a certificate to be sent to said secretary-treasurer to the effect that such sections shall become operative for the employees of the authority on the first day of January or on the first day of July, whichever first occurs, next following the expiration of three months after the date of such certificate.

(b) On and after the date when sections one to twenty-eight, inclusive, become operative for the employees of the Massachusetts Department of Transportation as set forth in paragraph (a) of this subdivision, the eligible employees of the authority shall become members of the Massachusetts Department of Transportation employees' retirement system; provided, however, that if any person was an employee of the authority on August fifteenth, nineteen hundred and sixty-seven and is otherwise eligible except that he is not so employed on the date when sections one to twenty-eight, inclusive, became operative for the employees of the Massachusetts Department of Transportation, such person or his surviving spouse shall be entitled to all the rights and benefits provided under said sections to which he or his surviving spouse would have been entitled had he become a member of the Massachusetts Department of Transportation employees' retirement system on the date it became operative.

(7) Acceptance by the Massachusetts Bay Transportation Authority. — (a) The Massachusetts Bay Transportation Authority may provide retirement benefits for its police employees if said authority by a vote duly recorded shall accept sections one to twenty-eight, inclusive, as far as applicable. A duly attested copy of such vote shall be filed by the treasurer of the authority in the office of the public employee retirement administration commission within thirty days after such vote. The public employee retirement administration commission shall, within fifteen days after the receipt of such attested copy, issue a certificate to be sent to said treasurer to the effect that such sections shall become operative for the said police employees of the authority on the first day of January or on the first day of July, whichever first occurs, next following the expiration of three months after the date of such certificate.

(b) On and after the date when sections one to twenty-eight, inclusive, become operative for the Massachusetts Bay Transportation Authority police as set forth in paragraph (a) of this subdivision, the eligible police officers of the authority shall become members of the Massachusetts Bay Transportation Authority police retirement system; provided, however, that if any person was a police officer of the authority on June first, nineteen hundred and sixty-nine, and is otherwise eligible except that he is not employed on the date when sections one to twenty-eight, inclusive, became operative for the Massachusetts Bay Transportation Authority police, such person or his surviving spouse shall be entitled to all the rights and benefits provided under said sections to which he or his surviving spouse would have been entitled had he become a member of the Massachusetts Bay Transportation Authority police retirement system on the date it becomes operative.

(8) Acceptance by the Massachusetts Housing Finance Agency. — (a) The Massachusetts Housing Finance Agency may provide retirement benefits for its employees if said agency by a vote duly recorded shall accept sections one to twenty-eight, inclusive, as far as applicable. A duly attested copy of such vote shall be filed by the treasurer of the agency in the office of the public employee retirement administration commission within thirty days after such vote. The public employee retirement administration commission shall, within fifteen days after the receipt of such attested copy, issue a certificate to be sent to said treasurer to the effect that such sections shall become operative for said employees of the agency on the first day of January or on the first day of July, whichever first occurs, next following the expiration of three months after the date of such certificate.

(b) On and after the date when sections one to twenty-eight, inclusive, become operative for the employees of the Massachusetts Housing Finance Agency as set forth in paragraph (a) of this subdivision, the eligible employees of the agency shall become members of the Massachusetts Housing Finance Agency employees' retirement system; provided, however, that if any person was an employee of the agency on September first, nineteen hundred and seventy-two and is otherwise eligible except that he is not so employed on the date when sections one to twenty-eight, inclusive, became operative for the employees of the Massachusetts Housing Finance Agency, such person or his surviving spouse shall be entitled to all the rights and benefits provided under said sections to which he or his surviving spouse would have been entitled had he become a member of the Massachusetts Housing Finance Agency employees' retirement system on the date it became operative.