Mass. Gen. Laws ch. 268A § 20
This section shall not apply if such financial interest consists of the ownership of less than one per cent of the stock of a corporation.
This section shall not apply (a) to a municipal employee who in good faith and within thirty days after he learns of an actual or prospective violation of this section makes full disclosure of his financial interest to the contracting agency and terminates or disposes of the interest, or (b) to a municipal employee who is not employed by the contracting agency or an agency which regulates the activities of the contracting agency and who does not participate in or have official responsibility for any of the activities of the contracting agency, if the contract is made after public notice or where applicable, through competitive bidding, and if the municipal employee files with the clerk of the city or town a statement making full disclosure of his interest and the interest of his immediate family, and if in the case of a contract for personal services (1) the services will be provided outside the normal working hours of the municipal employee, (2) the services are not required as part of the municipal employee's regular duties, the employee is compensated for not more than five hundred hours during a calendar year, (3) the head of the contracting agency makes and files with the clerk of the city or town a written certification that no employee of that agency is available to perform those services as part of their regular duties, and (4) the city council, board of selectmen or board of aldermen approve the exemption of his interest from this section, or (c) to a special municipal employee who does not participate in or have official responsibility for any of the activities of the contracting agency and who files with the clerk of the city or town a statement making full disclosure of his interest and the interests of his immediate family in the contract, or (d) to a special municipal employee who files with the clerk of the city, town or district a statement making full disclosure of his interest and the interests of his immediate family in the contract, if the city council or board of aldermen, if there is no city council, board of selectmen or the district prudential committee, approve the exemption of his interest from this section, or (e) to a municipal employee who receives benefits from programs funded by the United States or any other source in connection with the rental, improvement, or rehabilitation of his residence to the extent permitted by the funding agency, or (f) to a municipal employee if the contract is for personal services in a part time, call or volunteer capacity with the police, fire, rescue or ambulance department of a fire district, town or any city with a population of less than thirty-five thousand inhabitants; provided, however, that the head of the contracting agency makes and files with the clerk of the city, district or town a written certification that no employee of said agency is available to perform such services as part of his regular duties, and the city council, board of selectmen, board of aldermen or district prudential committee approve the exemption of his interest from this section or (g) to a municipal employee who has applied in the usual course and is otherwise eligible for a housing subsidy program administered by a local housing authority, unless the employee is employed by the local housing authority in a capacity in which he has responsibility for the administration of such subsidy programs or (h) to a municipal employee who is the owner of residential rental property and rents such property to a tenant receiving a rental subsidy administered by a local housing authority, unless such employee is employed by such local housing authority in a capacity in which he has responsibility for the administration of such subsidy programs.
This section shall not prohibit an employee or an official of a town from holding the position of selectman in such town nor in any way prohibit such employee from performing the duties of or receiving the compensation provided for such office; provided, however, that such selectman shall not, except as hereinafter provided, receive compensation for more than one office or position held in a town, but shall have the right to choose which compensation he shall receive; provided, further, that no such selectman may vote or act on any matter which is within the purview of the agency by which he is employed or over which he has official responsibility; and, provided further, that no such selectman shall be eligible for appointment to any such additional position while he is still a member of the board of selectmen or for six months thereafter. Any violation of the provisions of this paragraph which has substantially influenced the action taken by any municipal agency in any matter shall be grounds for avoiding, rescinding or cancelling the action on such terms as the interest of the municipality and innocent third parties may require.
This section shall not prohibit any elected official in a town, whether compensated or uncompensated for such elected position, from holding one or more additional elected positions, in such town, whether such additional elected positions are compensated or uncompensated.
This section shall not prohibit an employee of a municipality with a city or town council form of government from holding the elected office of councillor in such municipality, nor in any way prohibit such an employee from performing the duties of or receiving the compensation provided for such office; provided, however, that no such councillor may vote or act on any matter which is within the purview of the agency by which he is employed or over which he has official responsibility; and provided, further, that no councillor shall be eligible for appointment to such additional position while a member of said council or for six months thereafter. Any violation of the provisions of this paragraph which has substantially influenced the action taken by a municipal agency in any matter shall be grounds for avoiding, rescinding or cancelling such action on such terms as the interest of the municipality and innocent third parties require. No such elected councillor shall receive compensation for more than one office or position held in a municipality, but shall have the right to choose which compensation he shall receive.
This section shall not prohibit an employee of a housing authority in a municipality from holding any elective office, other than the office of mayor, in such municipality nor in any way prohibit such employee from performing the duties of or receiving the compensation provided for such office; provided, however, that such elected officer shall not, except as otherwise expressly provided, receive compensation for more than one office or position held in a municipality, but shall have the right to choose which compensation he shall receive; provided further that no such elected official may vote or act on any matter which is within the purview of the housing authority by which he is employed; and provided further that no such elected official shall be eligible for appointment to any such additional position while he is still serving in such elective office or for six months thereafter. Any violation of the provisions of this paragraph which has substantially influenced the action taken by the housing authority in any matter shall be grounds for avoiding, rescinding, or cancelling the action on such terms as the interest of the municipality and innocent third parties may require.
This section shall not prohibit an employee in a town having a population of less than three thousand five hundred persons from holding more than one appointed position with said town, provided that the board of selectmen approves the exemption of his interest from this section.
Mass. Gen. Laws ch. 268A, § 20