Mass. Gen. Laws ch. 54 § 86
Any voter who during the hours that polling places are open on the day of a special state election or the biennial state election or of any special or regular state primary or of a presidential primary is absent from the city or town where he is a voter by reason of being a specially qualified voter as defined in section one of chapter fifty, or his employment in another community, attendance at any institution of higher education or for any other reason or who will be unable to by reason of physical disability to cast his vote in person at the polling place or who for reasons of religious belief will be unable to cast his vote in person on the day of an election and whose application for an official absent voting ballot has been filed with the city or town clerk as provided in section eighty-nine, and certified under section ninety-one, may vote in accordance with sections eighty-seven to one hundred and three, inclusive. A voter who will be unable by reason of permanent physical disability to cast his vote in person at the polling place may file once with the city or town clerk a certificate executed by a registered physician who is personally acquainted with the voter and aware of his permanent physical disability, stating that it is reasonably certain because of permanent physical disability that the voter will be unable to cast his vote in person at the polling place on the day of the election. The city or town clerk shall maintain a list of such permanently disabled voters and such voters shall not be required to file any such certification thereafter with their applications for an absent voting ballot. Not later than twenty-eight days before every primary, preliminary election or election, the city or town clerk shall send to each voter whose name appears on the permanently disabled voters' list an application for an absent voting ballot, which application said clerk shall complete so far as possible except for the voter's signature.
Mass. Gen. Laws ch. 54, § 86