Mass. Gen. Laws ch. 53 § 37
The voting lists used at primaries shall contain the party enrollment of the voters whose names appear thereon established as provided in this section, in section thirty-eight, and in section forty-four of chapter fifty-one. Except as provided by section thirty-seven A, a voter desiring to vote in a primary shall give his name, and, if requested, his residence, to one of the ballot clerks, who shall distinctly announce the same, and, if the party enrolment of such voter is shown on the voting list, the name of the party in which he is enrolled. If the party enrollment of the voter is not shown on the voting list the ballot clerk shall ask such voter in which political party's primary he desires to vote, and the ballot clerk, upon reply, shall distinctly announce the name of such political party, and shall record the voter's selection upon the voting list. The ballot clerk shall then give the voter the ballot of the political party so requested.If the voter was unenrolled before selecting a party ballot, he shall continue to be unenrolled and shall be recorded as unenrolled in the current annual register of voters.
After marking his ballot the voter shall give his name, and, if requested, his residence, to the officer in charge of the voting list at the ballot box, who shall distinctly announce the same. If the party enrolment of the voter is shown on the voting list he shall also make announcement of such enrolment and the officer in charge of the ballot box shall, before the voter's ballot is deposited, ascertain that it is of the political party in which such voter is enrolled. If the enrolment of the voter is not shown on such voting list, the officer in charge of the ballot box shall announce the political party whose ballot the voter is about to deposit, and the officer in charge of the voting list shall repeat the same distinctly and record the same upon such voting list.
The voting lists used at primaries shall be returned to the city or town clerk to be retained in his custody as long as he retains the ballots cast, whereupon such voting lists shall be transmitted to the registrars of voters for preservation for two years, after the expiration of which they may be destroyed. Said officers shall, at any time after the primary, upon receiving a written request therefor signed by any person, furnish a copy of said list to such person upon the payment of a reasonable fee or shall allow such person to examine and copy such list without charge under such supervision as the clerk may reasonably require. The party enrolment of each voter, if any, shall be recorded in the current annual register of voters, and whenever a voter shall establish, cancel or change his enrolment it shall likewise be so recorded. In preparing the current annual register of voters, the party enrolment, if any, of each voter included therein, as shown by the register of voters for the preceding year, shall be transferred thereto. Upon receipt of a written request from a primary candidate or any officer of any ward, town or city committee or duly organized political committee for a copy of the party enrolment list of voters in any city or town, the board of registrars or the election commissioners, as the case may be, shall prepare said list and shall furnish at once the said list, free of charge, to the party requesting the same and they shall also furnish a copy of said list to any person on payment of a reasonable fee, not to exceed the cost of printing such list.
Mass. Gen. Laws ch. 53, § 37