Mass. Gen. Laws ch. 32 § 101
In the event of the death of any former employee who had been retired under the provisions of this chapter after having been found to be incapacitated for further duty by reason of injuries sustained while in the performance of his duties, or who had been retired for ordinary disability under the provisions of this chapter, under which retirement he was unable to provide for any annual allowance to be paid to his widow at the time of his death, there shall be paid to such widow an annual allowance in the amount of either $6,000 or, in a retirement system accepting the supplemental annual allowance as provided in this section, $9,000, or, in a retirement system accepting the supplemental annual allowance provided in the third paragraph, $12,000, subject to the provisions of paragraph (e) of section one hundred and two, for as long as she remains unremarried; provided, however, that any allowance payable under this section shall be in the alternative to any allowance to which such widow would be entitled under the provisions of any other section of this chapter. Any allowance which such widow may be receiving or any allowance which she may have potential rights to receive, based on her own service to the commonwealth or any political subdivision thereof, shall not make her ineligible to receive the allowance provided in this section. The allowance provided by this section shall be paid by the same retiring authority and from the same source as the allowance payable to the deceased former employee referred to in this section.
Notwithstanding the previous paragraph, a retirement system may accept a supplemental annual allowance fixed at the rate of $9,000, by a majority vote of the board of each such system, subject to the approval of the legislative body thereof. For the purposes of this section, "legislative body" shall mean, in the case of a city, the city council in accordance with its charter, in the case of a town, the town meeting, in the case of a county, the county retirement board advisory council, in the case of a region, the regional retirement board advisory council, in the case of a district, the district members and, in the case of an authority, the governing body of such authority. Acceptance shall be deemed to have occurred upon the filing of a certification of such votes with the commission.
Any retirement system may accept the supplemental annual allowance, provided for by this paragraph and fixed at the rate of $12,000, by a majority vote of the board of each such system, subject to the approval of the legislative body. Acceptance shall be deemed to have occurred upon the filing of a certification of such votes with the commission. For purposes of this section, the state teachers' and state employees' retirement systems shall be deemed to have accepted this paragraph.
Mass. Gen. Laws ch. 32, § 101