Mass. Gen. Laws ch. 175 § 93F
Any mutual fire company, or any company specified in the first paragraph of section ninety, which has and maintains a surplus to policyholders, including any guaranty capital or guaranty fund, at least equal to the minimum paid-up capital and assets that are on the effective date of this section required by this chapter of a stock insurance company transacting the same kind or kinds of business may issue non-assessable policies, and the provisions of section eighty-one relating to contingent liability of policyholders shall not apply to any such non-assessable policies. Any such mutual company shall keep on deposit with the state treasurer the sum of two hundred thousand dollars, subject to the provisions of section eighty-five A. This section shall not apply to any company unless such company or its predecessor or predecessors, if any, prior to merger or consolidation shall have been actively engaged in the insurance business in one or more states of the United States continuously for ten or more years. A company issuing a non-assessable policy under authority of this section may state therein, or on the filing back thereof, or in both such places, that such policy is non-assessable.
Mass. Gen. Laws ch. 175, § 93F