Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 180, § 17I

A single deduction on payroll schedules shall be made from the salary of any school teacher in an amount which such teacher may specify in writing to the city, town or district school committee by which he is employed; provided, however, that no specific deduction shall be made for the payment of contributions to political campaign committees or political campaign organizations. Any such authorization may be withdrawn by such teacher by giving at least sixty days' notice in writing of such withdrawal to said school committee. The treasurer of the city, town or district shall deduct from the salary of such teacher such amount as may be certified to him on the payroll and shall transmit the sum so deducted to the state teacher association of which such teacher is a member within thirty days; provided, that the city, town or district treasurer is satisfied by such evidence as he may require that the treasurer of such state teacher association has given a bond, in form approved by the commissioner of corporations and taxation, for the faithful performance of his duties, in a sum and with such surety or sureties as are satisfactory to the city, town or district treasurer. The provisions of this section shall take effect in each city, town or regional school district which accepts the provisions hereof by vote of its school committee.