Mass. Gen. Laws ch. 51 § 42A
Any person claiming to have the qualifications for voting in any city or town who, by reason of physical disability, is unable to appear in person to register may make application, in writing, to the registrars of voters of such city or town for registration in the manner hereinafter provided.
The application shall be made, not later than the third day before the last day for registration of voters under section twenty-six, to the registrars of voters of the city or town in which the applicant resides. Applications received after such third day shall not be acted upon.
The registrars shall seasonably after receipt of an application for registration under this section delegate two registrars, assistant registrars, or absent registration officers to visit the person making the same, and the said officers, equally representing the two political parties, if satisfied that the applicant is unable by reason of physical disability to appear in person to register, shall provide him with a blank affidavit of registration and shall witness the signing thereof. No such person shall be provided with an affidavit of registration after the close of registration nor in any city or town other than that in which he claims the right to vote; provided, however, if the applicant is in the military or naval service of the United States, he may so register up until four o'clock post meridian on the day preceding a primary election, preliminary election or election.
Mass. Gen. Laws ch. 51, § 42A