City and town halls will be open across the state until 8 p.m. for registration. Mail-in registration forms are available at local election offices and at the Elections Division in the office of the Secretary of State in Boston. Forms must be returned and postmarked by today.

Those registered either Democrat or Republican can only vote in their party's primary, unless they change their status to unenrolled by today. Unenrolled voters can revert to their previous party affiliation by filling out a form at the polls.

Anyone who has moved from one municipality to another must also register in their new community. For more information, call 800-462-VOTE (800-462-8683), or see one of the following state websites:

How to register to vote
How to apply for an absentee ballot