840 CMR, § 7.04
Any active or retired member of the appropriate system may qualify as a candidate by filing with the board a nomination paper or papers, containing the signatures and addresses of at least 20 active or retired members of the system. Nomination papers, in blank, shall be made available to candidates at least 90 days prior to the date of the election. The nomination paper or papers, containing the necessary number of qualified signatures and addresses shall be filed no later than 45 days prior to the date of the election. If the board determines that a candidate has filed nomination papers containing less than the required number of qualified signatures, the board shall declare the nomination papers invalid and shall notify the candidate of its determination.
840 CMR, § 7.04