Mont. Code Ann. § 33-4-407

An insurer may not accumulate any profits or pay any dividends. This provision does not prohibit an insurer from accumulating and maintaining surplus funds as required to be maintained by the insurer under this chapter or from accumulating and maintaining other voluntary reserves for purposes and in amounts that may be reasonable. Limitations on any accumulations and the purposes of the accumulations may be provided for in the insurer's bylaws.