Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 51, § 37A

The name and address of a voter that is not entered in the annual register pursuant to section 37 for 2 consecutive years and who during that time fails to vote in any election shall be maintained on an inactive voters list until such voter has failed to vote in two consecutive biennial state elections and has thereafter been notified, by mail, of such removal from the inactive voters list.