SECTION 1.  Notwithstanding the provisions of any general or special law to the contrary, a member, who is receiving a lesser retirement allowance in accordance with the terms of Option (c) of subdivision (2) of section 12 of chapter 32 of the General Laws, from a retirement system that accepts the provisions of this act, shall have his retirement allowance determined according to the table of mortality selected by the commission pursuant to section 336 of chapter 47 of the acts of 2004. Any retirement system may accept the provisions of this act by a majority vote of the board of each such system, subject to the approval of the legislative body. For the purposes of this act, “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.  For purposes of this act, the state teachers’ and state employees’ retirement systems shall be deemed to have accepted the provisions of this act.

SECTION 2.  The provisions of this act shall be prospective from the effective date of this act and shall not entitle any member or spouse of a deceased member to any retroactive benefits.