Mass. Gen. Laws ch. 175 § 110D
Every policy of insurance issued after January first, nineteen hundred and sixty-eight under the provisions of section one hundred and ten shall contain a provision that, in the event that the insured person leaves the group covered by such insurance, said person shall remain insured under such policy for a period of thirty-one days thereafter unless, during such period, he shall otherwise be entitled to similar benefits. The provisions of this paragraph shall apply to any policy issued or renewed within or without the commonwealth and which covers residents of the commonwealth.
In addition, every such policy of insurance which is issued or subsequently renewed by agreement between the insurer and the policyholder, within or without the commonwealth, during the period this provision is effective, shall include coverage such that, in the event that the insured person leaves the group covered by such insurance because his employment is terminated due to a plant closing or covered partial closing as those terms are defined in section seventy-one A of chapter one hundred and fifty-one A, said person shall remain insured under such policy for a period of ninety days thereafter unless, during such period, he shall otherwise be entitled to similar benefits.
Mass. Gen. Laws ch. 175, § 110D