Mass. Gen. Laws ch. 32B § 11
The appropriate public authority in each county, except Worcester county, city, town or district which has accepted this chapter shall from time to time issue rules and regulations establishing a schedule of group life, accidental death and dismemberment insurance for each employee and a schedule of hospital, surgical, medical, dental and other health insurance benefits for active and retired employees and their dependents which schedules shall be the maximum schedules of insurance coverage to be made available for active and retired employees and their dependents of the governmental unit.
The appropriate public authority in each city, town or district which has accepted this chapter may notify the county commissioners of its election to participate in the schedule of benefits made available by said county, except Worcester county, for its employees; and subject to the approval of said commissioners the employees of the city, town or district so applying will become insured at the earliest practicable date, but in no event later than the commencement of the next policy anniversary date. Such coverage shall be furnished at uniform premium rates to all participating counties, except Worcester county, cities, towns and districts. Two or more counties establishing identical benefit schedules may join under one such policy or policies and may be considered as one governmental unit. The county commissioners may at their discretion establish a central administrative office and employ such personnel as may be necessary to carry out the provisions of this chapter.
Notwithstanding any charter or ordinance to the contrary, the appropriate public authority of the cities of Cambridge, Chelsea, Everett, Malden, Medford, Melrose, Quincy, Revere and Somerville may notify the appropriate public authority of the city of Boston of its election to participate in the schedule of benefits made available by the city of Boston for its employees and, subject to the approval of the appropriate public authority of the city of Boston and under such terms and conditions and rules and regulations as may be prescribed from time to time by the appropriate public authority of the city of Boston, the employees of the city so applying shall become insured at the earliest practicable date as participants in a city of Boston group health or life benefit plan. The withdrawal of each individual city's employees from each individual city's group health or life benefit plan and the subsequent inclusion of that city's employees in the city of Boston's group health life benefit plan shall coincide with annual open enrollment periods. Nothing in this paragraph shall prohibit the appropriate public authority of the city of Boston from prohibiting participation by applying cities in certain benefit programs made available by the city of Boston for its employees. Nothing in this paragraph shall prevent a participating city from withdrawing from participation upon reasonable notice provided by the appropriate public authority of the participating city to the appropriate public authority of the city of Boston. A city granted approval to participate in the city of Boston's schedule of benefits that incurs costs by so joining or exiting including, but not limited to, paying for claims which have been incurred but not yet paid may amortize such costs over a period of not more that 10 years from the date of such approval or exit.
Nothing in this section shall abrogate any provision of chapter 150E or any collective bargaining agreement with respect to health benefits or impact adversely the rights and benefits of public employees pursuant to any collective bargaining agreement.
Upon request, the commission shall furnish information and advisory rulings in accordance with the provisions of section eight of chapter thirty A.
Mass. Gen. Laws ch. 32B, § 11