MA Gen L ch 54 § 1 (2021)
2021 Massachusetts General Laws|Part I - Administration of the Government|Title VIII - Elections|Chapter 54 - Elections|Section 1 - Decennial Division of Cities Into Wards and Precincts

Section 1. In the year 2001, and every tenth year thereafter, no later than June fifteenth, a city, by vote of its city council may, or if the existing wards in such city do not contain, as nearly as can be ascertained, an equal number of inhabitants, shall make a new division of its territory into such number of wards as may be fixed by law. Any such vote of a city council hereunder dividing a city into wards shall, at the same time, divide each ward into such number of precincts as is required by section two. Within 7 days of the last day the city council may vote, the city clerk shall give written notice to the state secretary of the number and designation of wards and precincts provided for in this section and in section two, together with an official map and description of said wards and precincts indicating, as nearly as can be ascertained, the numbers of inhabitants residing therein. The provisions of this section and section two shall not apply to any city which has a special law to the contrary covering the procedure for the division of wards and precincts.  The state secretary shall make available to the local election districts review commission, for its scrutiny, the written notices, maps and descriptive information submitted to him by city clerks in reference to the new or unrevised wards and precincts of their respective cities under this section. If the said commission shall find that any such plan of new or unrevised wards or precincts of any city conflicts with the applicable requirements of this chapter, or is of questionable constitutionality, it shall transmit a written notice of such findings, with a clear indication of the deficiencies of such plan, to the mayor of such city, or in a city having a council-manager form of government to the city manager, not later than 35 days after the final day to give written notice to the state secretary. Said mayor or city manager shall, within 7 days following his receipt of such notice, present to the city council of such city his recommendations for a division of the city into wards and precincts free of the defects cited by the commission. If the city council shall fail to ordain such division, or a substitute division, conformable to this chapter within 7 days after said presentation by said mayor or city manager, he shall issue forthwith, not later than 14 days after the last day to receive notice from the local election district review commission, an executive order making a division of said city into wards and precincts subject to the approval of the local election districts review commission which shall take effect according to the provisions of this chapter, as though it had been ordained by the city council.  For any city that fails to act by the forty-ninth day following the final day to give notice to the state secretary, the local election districts review commission shall, within 15 days, make such division of the city into wards and precincts or appoint a master who shall make such division which shall be subject to approval and amendment by the commission. The cost of redistricting by a master shall be paid by the city.  Should the state secretary determine that decennial federal census figures are available at such time as to allow this process to begin earlier, the state secretary shall designate the date on which such process shall begin.